text:
Nitrous acid

Nitrous acid (molecular formula ) is a weak and monoprotic acid known only in solution, in the gas phase, and in the form of nitrite salts. It was discovered by Carl Wilhelm Scheele, who called it "phlogisticated acid of niter". Nitrous acid is used to make diazonium salts from amines. The resulting diazonium salts are reagents in azo coupling reactions to give azo dyes.

Structure
In the gas phase, the planar nitrous acid molecule can adopt both a syn and an anti form. The anti form predominates at room temperature, and IR measurements indicate it is more stable by around 2.3 kJ/mol.

Preparation
Nitrous acid is usually generated by acidification of aqueous solutions of sodium nitrite with a mineral acid. The acidification is usually conducted at ice temperatures, and the HNO2 is consumed in situ. Free nitrous acid or concentrated solutions are unstable and decompose rapidly.

Nitrous acid can also be produced by dissolving dinitrogen trioxide in water according to the equation
 * N2O3 + H2O → 2 HNO2

Reactions
Nitrous acid is the main chemophore in the Liebermann reagent, used to spot-test for alkaloids.

Decomposition
Gaseous nitrous acid, which is rarely encountered, decomposes into nitrogen dioxide, nitric oxide, and water:
 * 2 HNO2 → NO2 + NO + H2O

Nitrogen dioxide disproportionates into nitric acid and nitrous acid in aqueous solution:

 * 2 NO2 + H2O → HNO3 + HNO2

In warm or concentrated solutions, the overall reaction amounts to production of nitric acid, water, and nitric oxide:

 * 3 HNO2 → HNO3 + 2 NO + H2O

The nitric oxide can subsequently be re-oxidized by air to nitric acid, making the overall reaction:

 * 2 HNO2 + O2 → 2 HNO3

Reduction
With I− and Fe2+ ions, NO is formed:

 * 2 HNO2 + 2 KI + 2 H2SO4 → I2 + 2 NO + 2 H2O + 2 K2SO4
 * 2 HNO2 + 2 FeSO4 + 2 H2SO4 → Fe2(SO4)3 + 2 NO + 2 H2O + K2SO4

With Sn2+ ions, N2O is formed:

 * 2 HNO2 + 6 HCl + 2 SnCl2 → 2 SnCl4 + N2O + 3 H2O + 2 KCl

With SO2 gas, NH2OH is formed:

 * 2 HNO2 + 6 H2O + 4 SO2 → 3 H2SO4 + K2SO4 + 2 NH2OH

With Zn in alkali solution, NH3 is formed:

 * 5 H2O + KNO2 + 3 Zn → NH3 + KOH + 3 Zn(OH)2

With, both HN3 and (subsequently) N2 gas are formed:

 * HNO2 + [N2H5]+ → HN3 + H2O + H3O+

 * HNO2 + HN3 → N2O + N2 + H2O

Oxidation by nitrous acid has a kinetic control over thermodynamic control, this is best illustrated that dilute nitrous acid is able to oxidize I− to I2, but dilute nitric acid cannot.

 * I2 + 2 e− ⇌ 2 I− Eo = +0.54 V

 * + 3 H+ + 2 e− ⇌ HNO2 + H2O Eo = +0.93 V

 * HNO2 + H+ + e− ⇌ NO + H2O Eo = +0.98 V

It can be seen that the values of E$o cell$ for these reactions are similar, but nitric acid is a more powerful oxidizing agent. Base on the fact that dilute nitrous acid can oxidize iodide into iodine, it can be deduced that nitrous is a faster, rather than a more powerful, oxidizing agent than dilute nitric acid.

Organic chemistry
Nitrous acid is used to prepare diazonium salts:
 * HNO2 +  ArNH2  +  H+  →     +  2 H2O

where Ar is an aryl group.

Such salts are widely used in organic synthesis, e.g., for the Sandmeyer reaction and in the preparation azo dyes, brightly colored compounds that are the basis of a qualitative test for anilines. Nitrous acid is used to destroy toxic and potentially explosive sodium azide. For most purposes, nitrous acid is usually formed in situ by the action of mineral acid on sodium nitrite: It is mainly blue in colour

 * NaNO2 + HCl →  HNO2  +  NaCl
 * 2 NaN3 + 2 HNO2 →   3 N2 + 2 NO + 2 NaOH

Reaction with two α-hydrogen atoms in ketones creates oximes, which may be further oxidized to a carboxylic acid, or reduced to form amines. This process is used in the commercial production of adipic acid.

Nitrous acid reacts rapidly with aliphatic alcohols to produce alkyl nitrites, which are potent vasodilators:

 * (CH3)2CHCH2CH2OH + HNO2 → (CH3)2CHCH2CH2ONO + H2O

The carcinogens called nitrosamines are produced, usually not intentionally, by the reaction of nitrous acid with secondary amines:
 * HNO2 +  R2NH  →  R2N-NO  +  H2O

Atmosphere of the Earth
Nitrous acid is involved in the ozone budget of the lower atmosphere, the troposphere. The heterogeneous reaction of nitric oxide (NO) and water produces nitrous acid. When this reaction takes place on the surface of atmospheric aerosols, the product readily photolyses to hydroxyl radicals.

DNA damage and mutation
Treatment of Escherichia coli cells with nitrous acid causes damage to the cell’s DNA including deamination of cytosine to uracil, and these damages are subject to repair by specific enzymes. Also, nitrous acid causes base substitution mutations in organisms with double-stranded DNA.

title: Nitrous acid


text:
Gas exchange

Gas exchange is the physical process by which gases move passively by diffusion across a surface. For example, this surface might be the air/water interface of a water body, the surface of a gas bubble in a liquid, a gas-permeable membrane, or a biological membrane that forms the boundary between an organism and its extracellular environment.

Gases are constantly consumed and produced by cellular and metabolic reactions in most living things, so an efficient system for gas exchange between, ultimately, the interior of the cell(s) and the external environment is required. Small, particularly unicellular organisms, such as bacteria and protozoa, have a high surface-area to volume ratio. In these creatures the gas exchange membrane is typically the cell membrane. Some small multicellular organisms, such as flatworms, are also able to perform sufficient gas exchange across the skin or cuticle that surrounds their bodies. However, in most larger organisms, which have small surface-area to volume ratios, specialised structures with convoluted surfaces such as gills, pulmonary alveoli and spongy mesophylls provide the large area needed for effective gas exchange. These convoluted surfaces may sometimes be internalised into the body of the organism. This is the case with the alveoli, which form the inner surface of the mammalian lung, the spongy mesophyll, which is found inside the leaves of some kinds of plant, or the gills of those molluscs that have them, which are found in the mantle cavity.

In aerobic organisms, gas exchange is particularly important for respiration, which involves the uptake of oxygen and release of carbon dioxide. Conversely, in oxygenic photosynthetic organisms such as most land plants, uptake of carbon dioxide and release of both oxygen and water vapour are the main gas-exchange processes occurring during the day. Other gas-exchange processes are important in less familiar organisms: e.g. carbon dioxide, methane and hydrogen are exchanged across the cell membrane of methanogenic archaea. In nitrogen fixation by diazotrophic bacteria, and denitrification by heterotrophic bacteria (such as Paracoccus denitrificans and various pseudomonads), nitrogen gas is exchanged with the environment, being taken up by the former and released into it by the latter, while giant tube worms rely on bacteria to oxidize hydrogen sulfide extracted from their deep sea environment, using dissolved oxygen in the water as an electron acceptor.

Diffusion only takes place with a concentration gradient. Gases will flow from a high concentration to a low concentration. A high oxygen concentration in the alveoli and low oxygen concentration in the capillaries causes oxygen to move into the capillaries. A high carbon dioxide concentration in the capillaries and low carbon dioxide concentration in the alveoli causes carbon dioxide to move into the alveoli.

Diffusion and surface area
The exchange of gases occurs as a result of diffusion down a concentration gradient. Gas molecules move from a region in which they are at high concentration to one in which they are at low concentration. Diffusion is a passive process, meaning that no energy is required to power the transport, and it follows Fick's Law:

 * $$J = -D \frac{d \varphi}{d x} $$

In relation to a typical biological system, where two compartments ('inside' and 'outside'), are separated by a membrane barrier, and where a gas is allowed to spontaneously diffuse down its concentration gradient:
 * J is the flux, the amount of gas diffusing per unit area of membrane per unit time. Note that this is already scaled for the area of the membrane.
 * D is the diffusion coefficient, which will differ from gas to gas, and from membrane to membrane, according to the size of the gas molecule in question, and the nature of the membrane itself (particularly its viscosity, temperature and hydrophobicity).
 * φ is the concentration of the gas.
 * x is the position across the thickness of the membrane.
 * dφ/dx is therefore the concentration gradient across the membrane. If the two compartments are individually well-mixed, then this is simplifies to the difference in concentration of the gas between the inside and outside compartments divided by the thickness of the membrane.
 * The negative sign indicates that the diffusion is always in the direction that - over time - will destroy the concentration gradient, i.e. the gas moves from high concentration to low concentration until eventually the inside and outside compartments reach equilibrium.

Gases must first dissolve in a liquid in order to diffuse across a membrane, so all biological gas exchange systems require a moist environment. In general, the higher the concentration gradient across the gas-exchanging surface, the faster the rate of diffusion across it. Conversely, the thinner the gas-exchanging surface (for the same concentration difference), the faster the gases will diffuse across it.

In the equation above, J is the flux expressed per unit area, so increasing the area will make no difference to its value. However, an increase in the available surface area, will increase the amount of gas that can diffuse in a given time. This is because the amount of gas diffusing per unit time (dq/dt) is the product of J and the area of the gas-exchanging surface, A:

 * $$\frac{d q}{d t} = J A$$

Single-celled organisms such as bacteria and amoebae do not have specialised gas exchange surfaces, because they can take advantage of the high surface area they have relative to their volume. The amount of gas an organism produces (or requires) in a given time will be in rough proportion to the volume of its cytoplasm. The volume of a unicellular organism is very small, therefore it produces (and requires) a relatively small amount of gas in a given time. In comparison to this small volume, the surface area of its cell membrane is very large, and adequate for its gas-exchange needs without further modification. However, as an organism increases in size, its surface area and volume do not scale in the same way. Consider an imaginary organism that is a cube of side-length, L. Its volume increases with the cube (L3) of its length, but its external surface area increases only with the square (L2) of its length. This means the external surface rapidly becomes inadequate for the rapidly increasing gas-exchange needs of a larger volume of cytoplasm. Additionally, the thickness of the surface that gases must cross (dx in Fick's Law) can also be larger in larger organisms: in the case of a single-celled organism, a typical cell membrane is only 10 nm thick; but in larger organisms such as roundworms (Nematoda) the equivalent exchange surface - the cuticle - is substantially thicker at 0.5 μm.

Interaction with circulatory systems

In multicellular organisms therefore, specialised respiratory organs such as gills or lungs are often used to provide the additional surface area for the required rate of gas exchange with the external environment. However the distances between the gas exchanger and the deeper tissues are often too great for diffusion to meet gaseous requirements of these tissues. The gas exchangers are therefore frequently coupled to gas-distributing circulatory systems, which transport the gases evenly to all the body tissues regardless of their distance from the gas exchanger.

Some multicellular organisms such as flatworms (Platyhelminthes) are relatively large but very thin, allowing their outer body surface to act as a gas exchange surface without the need for a specialised gas exchange organ. Flatworms therefore lack gills or lungs, and also lack a circulatory system. Other multicellular organisms such as sponges (Porifera) have an inherently high surface area, because they are very porous and/or branched. Sponges do not require a circulatory system or specialised gas exchange organs, because their feeding strategy involves one-way pumping of water through their porous bodies using flagellated collar cells. Each cell of the sponge's body is therefore exposed to a constant flow of fresh oxygenated water. They can therefore rely on diffusion across their cell membranes to carry out the gas exchange needed for respiration.

In organisms that have circulatory systems associated with their specialized gas-exchange surfaces, a great variety of systems are used for the interaction between the two.

In a countercurrent flow system, air (or, more usually, the water containing dissolved air) is drawn in the opposite direction to the flow of blood in the gas exchanger. A countercurrent system such as this maintains a steep concentration gradient along the length of the gas-exchange surface (see lower diagram in Fig. 2). This is the situation seen in the gills of fish and many other aquatic creatures. The gas-containing environmental water is drawn unidirectionally across the gas-exchange surface, with the blood-flow in the gill capillaries beneath flowing in the opposite direction. Although this theoretically allows almost complete transfer of a respiratory gas from one side of the exchanger to the other, in fish less than 80% of the oxygen in the water flowing over the gills is generally transferred to the blood.

Alternative arrangements are cross current systems found in birds. and dead-end air-filled sac systems found in the lungs of mammals. In a cocurrent flow system, the blood and gas (or the fluid containing the gas) move in the same direction through the gas exchanger. This means the magnitude of the gradient is variable along the length of the gas-exchange surface, and the exchange will eventually stop when an equilibrium has been reached (see upper diagram in Fig. 2). Cocurrent flow gas exchange systems are not known to be used in nature.

Mammals
The gas exchanger in mammals is internalized to form lungs, as it is in most of the larger land animals. Gas exchange occurs in microscopic dead-end air-filled sacs called alveoli, where a very thin membrane (called the blood-air barrier) separates the blood in the alveolar capillaries (in the walls of the alveoli) from the alveolar air in the sacs.

Exchange membrane
The membrane across which gas exchange takes place in the alveoli (i.e. the blood-air barrier) is extremely thin (in humans, on average, 2.2 μm thick). It consists of the alveolar epithelial cells, their basement membranes and the endothelial cells of the pulmonary capillaries (Fig. 4). The large surface area of the membrane comes from the folding of the membrane into about 300 million alveoli, with diameters of approximately 75-300 μm each. This provides an extremely large surface area (approximately 145 m2) across which gas exchange can occur.

Alveolar air

Air is brought to the alveoli in small doses (called the tidal volume), by breathing in (inhalation) and out (exhalation) through the respiratory airways, a set of relatively narrow and moderately long tubes which start at the nose or mouth and end in the alveoli of the lungs in the chest. Air moves in and out through the same set of tubes, in which the flow is in one direction during inhalation, and in the opposite direction during exhalation.

During each inhalation, at rest, approximately 500 ml of fresh air flows in through the nose. It is warmed and moistened as it flows through the nose and pharynx. By the time it reaches the trachea the inhaled air's temperature is 37 °C and it is saturated with water vapor. On arrival in the alveoli it is diluted and thoroughly mixed with the approximately 2.5–3.0 liters of air that remained in the alveoli after the last exhalation. This relatively large volume of air that is semi-permanently present in the alveoli throughout the breathing cycle is known as the functional residual capacity (FRC).

At the beginning of inhalation the airways are filled with unchanged alveolar air, left over from the last exhalation. This is the dead space volume, which is usually about 150 ml. It is the first air to re-enter the alveoli during inhalation. Only after the dead space air has returned to the alveoli does the remainder of the tidal volume (500 ml - 150 ml = 350 ml) enter the alveoli. The entry of such a small volume of fresh air with each inhalation, ensures that the composition of the FRC hardly changes during the breathing cycle (Fig. 5). The alveolar partial pressure of oxygen remains very close to 13–14 kPa (100 mmHg), and the partial pressure of carbon dioxide varies minimally around 5.3 kPa (40 mmHg) throughout the breathing cycle (of inhalation and exhalation). The corresponding partial pressures of oxygen and carbon dioxide in the ambient (dry) air at sea level are 21 kPa (160 mmHg) and 0.04 kPa (0.3 mmHg) respectively.

This alveolar air, which constitutes the FRC, completely surrounds the blood in the alveolar capillaries (Fig. 6). Gas exchange in mammals occurs between this alveolar air (which differs significantly from fresh air) and the blood in the alveolar capillaries. The gases on either side of the gas exchange membrane equilibrate by simple diffusion. This ensures that the partial pressures of oxygen and carbon dioxide in the blood leaving the alveolar capillaries, and ultimately circulates throughout the body, are the same as those in the FRC.

The marked difference between the composition of the alveolar air and that of the ambient air can be maintained because the functional residual capacity is contained in dead-end sacs connected to the outside air by long, narrow, tubes (the airways: nose, pharynx, larynx, trachea, bronchi and their branches and sub-branches down to the bronchioles). This anatomy, and the fact that the lungs are not emptied and re-inflated with each breath, provides mammals with a "portable atmosphere", whose composition differs significantly from the present-day ambient air.

The composition of the air in the FRC is carefully monitored, by measuring the partial pressures of oxygen and carbon dioxide in the arterial blood. If either gas pressure deviates from normal, reflexes are elicited that change the rate and depth of breathing in such a way that normality is restored within seconds or minutes.

Pulmonary circulation
All the blood returning from the body tissues to the right side of the heart flows through the alveolar capillaries before being pumped around the body again. On its passage through the lungs the blood comes into close contact with the alveolar air, separated from it by a very thin diffusion membrane which is only, on average, about 2 μm thick. The gas pressures in the blood will therefore rapidly equilibrate with those in the alveoli, ensuring that the arterial blood that circulates to all the tissues throughout the body has an oxygen tension of 13−14 kPa (100 mmHg), and a carbon dioxide tension of 5.3 kPa (40 mmHg). These arterial partial pressures of oxygen and carbon dioxide are homeostatically controlled. A rise in the arterial $$P_{{\mathrm{CO}}_2}$$, and, to a lesser extent, a fall in the arterial $$P_{{\mathrm{O}}_2}$$, will reflexly cause deeper and faster breathing until the blood gas tensions return to normal. The converse happens when the carbon dioxide tension falls, or, again to a lesser extent, the oxygen tension rises: the rate and depth of breathing are reduced until blood gas normality is restored.

Since the blood arriving in the alveolar capillaries has a $$P_{{\mathrm{O}}_2}$$ of, on average, 6 kPa (45 mmHg), while the pressure in the alveolar air is 13 kPa (100 mmHg), there will be a net diffusion of oxygen into the capillary blood, changing the composition of the 3 liters of alveolar air slightly. Similarly, since the blood arriving in the alveolar capillaries has a $$P_{{\mathrm{CO}}_2}$$ of also about 6 kPa (45 mmHg), whereas that of the alveolar air is 5.3 kPa (40 mmHg), there is a net movement of carbon dioxide out of the capillaries into the alveoli. The changes brought about by these net flows of individual gases into and out of the functional residual capacity necessitate the replacement of about 15% of the alveolar air with ambient air every 5 seconds or so. This is very tightly controlled by the continuous monitoring of the arterial blood gas tensions (which accurately reflect partial pressures of the respiratory gases in the alveolar air) by the aortic bodies, the carotid bodies, and the blood gas and pH sensor on the anterior surface of the medulla oblongata in the brain. There are also oxygen and carbon dioxide sensors in the lungs, but they primarily determine the diameters of the bronchioles and pulmonary capillaries, and are therefore responsible for directing the flow of air and blood to different parts of the lungs.

It is only as a result of accurately maintaining the composition of the 3 liters alveolar air that with each breath some carbon dioxide is discharged into the atmosphere and some oxygen is taken up from the outside air. If more carbon dioxide than usual has been lost by a short period of hyperventilation, respiration will be slowed down or halted until the alveolar $$P_{{\mathrm{CO}}_2}$$ has returned to 5.3 kPa (40 mmHg). It is therefore strictly speaking untrue that the primary function of the respiratory system is to rid the body of carbon dioxide "waste". In fact the total concentration of carbon dioxide in arterial blood is about 26 mM (or 58 ml per 100 ml), compared to the concentration of oxygen in saturated arterial blood of about 9 mM (or 20 ml per 100 ml blood). This large concentration of carbon dioxide plays a pivotal role in the determination and maintenance of the pH of the extracellular fluids. The carbon dioxide that is breathed out with each breath could probably be more correctly be seen as a byproduct of the body's extracellular fluid carbon dioxide and pH homeostats

If these homeostats are compromised, then a respiratory acidosis, or a respiratory alkalosis will occur. In the long run these can be compensated by renal adjustments to the H+ and HCO3− concentrations in the plasma; but since this takes time, the hyperventilation syndrome can, for instance, occur when agitation or anxiety cause a person to breathe fast and deeply thus blowing off too much CO2 from the blood into the outside air, precipitating a set of distressing symptoms which result from an excessively high pH of the extracellular fluids.

Oxygen has a very low solubility in water, and is therefore carried in the blood loosely combined with hemoglobin. The oxygen is held on the hemoglobin by four ferrous iron-containing heme groups per hemoglobin molecule. When all the heme groups carry one O2 molecule each the blood is said to be "saturated" with oxygen, and no further increase in the partial pressure of oxygen will meaningfully increase the oxygen concentration of the blood. Most of the carbon dioxide in the blood is carried as HCO3− ions in the plasma. However the conversion of dissolved CO2 into HCO3− (through the addition of water) is too slow for the rate at which the blood circulates through the tissues on the one hand, and alveolar capillaries on the other. The reaction is therefore catalyzed by carbonic anhydrase, an enzyme inside the red blood cells. The reaction can go in either direction depending on the prevailing partial pressure of carbon dioxide. A small amount of carbon dioxide is carried on the protein portion of the hemoglobin molecules as carbamino groups. The total concentration of carbon dioxide (in the form of bicarbonate ions, dissolved CO2, and carbamino groups) in arterial blood (i.e. after it has equilibrated with the alveolar air) is about 26 mM (or 58 ml/100 ml), compared to the concentration of oxygen in saturated arterial blood of about 9 mM (or 20 ml/100 ml blood).

Fish

The dissolved oxygen content in fresh water is approximately 8–10 milliliters per liter compared to that of air which is 210 milliliters per liter. Water is 800 times more dense than air and 100 times more viscous. Therefore, oxygen has a diffusion rate in air 10,000 times greater than in water. The use of sac-like lungs to remove oxygen from water would therefore not be efficient enough to sustain life. Rather than using lungs, gaseous exchange takes place across the surface of highly vascularized gills. Gills are specialised organs containing filaments, which further divide into lamellae. The lamellae contain capillaries that provide a large surface area and short diffusion distances, as their walls are extremely thin. Gill rakers are found within the exchange system in order to filter out food, and keep the gills clean.

Gills use a countercurrent flow system that increases the efficiency of oxygen-uptake (and waste gas loss). Oxygenated water is drawn in through the mouth and passes over the gills in one direction while blood flows through the lamellae in the opposite direction. This countercurrent maintains steep concentration gradients along the entire length of each capillary (see the diagram in the "Interaction with circulatory systems" section above). Oxygen is able to continually diffuse down its gradient into the blood, and the carbon dioxide down its gradient into the water. The deoxygenated water will eventually pass out through the operculum (gill cover). Although countercurrent exchange systems theoretically allow an almost complete transfer of a respiratory gas from one side of the exchanger to the other, in fish less than 80% of the oxygen in the water flowing over the gills is generally transferred to the blood.

Amphibians
Amphibians have three main organs involved in gas exchange: the lungs, the skin, and the gills, which can be used singly or in a variety of different combinations. The relative importance of these structures differs according to the age, the environment and species of the amphibian. The skin of amphibians and their larvae are highly vascularised, leading to relatively efficient gas exchange when the skin is moist. The larvae of amphibians, such as the pre-metamorphosis tadpole stage of frogs, also have external gills. The gills are absorbed into the body during metamorphosis, after which the lungs will then take over. The lungs are usually simpler than in the other land vertebrates, with few internal septa and larger alveoli; however, toads, which spend more time on land, have a larger alveolar surface with more developed lungs. To increase the rate of gas exchange by diffusion, amphibians maintain the concentration gradient across the respiratory surface using a process called buccal pumping. The lower floor of the mouth is moved in a "pumping" manner, which can be observed by the naked eye.

Reptiles
All reptiles breathe using lungs. In squamates (the lizards and snakes) ventilation is driven by the axial musculature, but this musculature is also used during movement, so some squamates rely on buccal pumping to maintain gas exchange efficiency.

Due to the rigidity of turtle and tortoise shells, significant expansion and contraction of the chest is difficult. Turtles and tortoises depend on muscle layers attached to their shells, which wrap around their lungs to fill and empty them. Some aquatic turtles can also pump water into a highly vascularised mouth or cloaca to achieve gas-exchange.

Crocodiles have a structure similar to the mammalian diaphragm - the diaphragmaticus - but this muscle helps create a unidirectional flow of air through the lungs rather than a tidal flow: this is more similar to the air-flow seen in birds than that seen in mammals. During inhalation, the diaphragmaticus pulls the liver back, inflating the lungs into the space this creates. Air flows into the lungs from the bronchus during inhalation, but during exhalation, air flows out of the lungs into the bronchus by a different route: this one-way movement of gas is achieved by aerodynamic valves in the airways.

Birds
Birds have lungs but no diaphragm. They rely mostly on air sacs for ventilation. These air sacs do not play a direct role in gas exchange, but help to move air unidirectionally across the gas exchange surfaces in the lungs. During inhalation, fresh air is taken from the trachea down into the posterior air sacs and into the parabronchi which lead from the posterior air sacs into the lung. The air that enters the lungs joins the air which is already in the lungs, and is drawn forward across the gas exchanger into anterior air sacs. During exhalation, the posterior air sacs force air into the same parabronchi of the lungs, flowing in the same direction as during inhalation, allowing continuous gas exchange irrespective of the breathing cycle. Air exiting the lungs during exhalation joins the air being expelled from the anterior air sacs (both consisting of "spent air" that has passed through the gas exchanger) entering the trachea to be exhaled  (Fig. 10). Selective bronchoconstriction at the various bronchial branch points ensures that the air does not ebb and flow through the bronchi during inhalation and exhalation, as it does in mammals, but follows the paths described above.

The unidirectional airflow through the parabronchi exchanges respiratory gases with a crosscurrent blood flow (Fig. 9). The partial pressure of O2 ($$P_{{\mathrm{O}}_2}$$) in the parabronchioles declines along their length as O2 diffuses into the blood. The capillaries leaving the exchanger near the entrance of airflow take up more O2 than capillaries leaving near the exit end of the parabronchi. When the contents of all capillaries mix, the final $$P_{{\mathrm{O}}_2}$$ of the mixed pulmonary venous blood is higher than that of the exhaled air, but lower than that of the inhaled air.

Plants
Gas exchange in plants is dominated by the roles of carbon dioxide, oxygen and water vapor. is the only carbon source for autotrophic growth by photosynthesis, and when a plant is actively photosynthesising in the light, it will be taking up carbon dioxide, and losing water vapor and oxygen. At night, plants respire, and gas exchange partly reverses: water vapor is still lost (but to a smaller extent), but oxygen is now taken up and carbon dioxide released.

Plant gas exchange occurs mostly through the leaves. Gas exchange between a leaf and the atmosphere occurs simultaneously through two pathways: 1) epidermal cells and cuticular waxes (usually referred as 'cuticle') which are always present at each leaf surface, and 2) stomata, which typically control the majority of the exchange. Gases enter into the photosynthetic tissue of the leaf through dissolution onto the moist surface of the palisade and spongy mesophyll cells. The spongy mesophyll cells are loosely packed, allowing for an increased surface area, and consequently an increased rate of gas-exchange. Uptake of carbon dioxide necessarily results in some loss of water vapor, because both molecules enter and leave by the same stomata, so plants experience a gas exchange dilemma: gaining enough without losing too much water. Therefore, water loss from other parts of the leaf is minimised by the waxy cuticle on the leaf's epidermis. The size of a stoma is regulated by the opening and closing of its two guard cells: the turgidity of these cells determines the state of the stomatal opening, and this itself is regulated by water stress. Plants showing crassulacean acid metabolism are drought-tolerant xerophytes and perform almost all their gas-exchange at night, because it is only during the night that these plants open their stomata. By opening the stomata only at night, the water vapor loss associated with carbon dioxide uptake is minimised. However, this comes at the cost of slow growth: the plant has to store the carbon dioxide in the form of malic acid for use during the day, and it cannot store unlimited amounts.

Gas exchange measurements are important tools in plant science: this typically involves sealing the plant (or part of a plant) in a chamber and measuring changes in the concentration of carbon dioxide and water vapour with an infrared gas analyzer. If the environmental conditions (humidity, concentration, light and temperature) are fully controlled, the measurements of  uptake and water release reveal important information about the  assimilation and transpiration rates. The intercellular concentration reveals important information about the photosynthetic condition of the plants. Simpler methods can be used in specific circumstances: hydrogencarbonate indicator can be used to monitor the consumption of in a solution containing a single plant leaf at different levels of light intensity, and oxygen generation by the pondweed Elodea can be measured by simply collecting the gas in a submerged test-tube containing a small piece of the plant.

Invertebrates
The mechanism of gas exchange in invertebrates depends their size, feeding strategy, and habitat (aquatic or terrestrial).

The sponges (Porifera) are sessile creatures, meaning they are unable to move on their own and normally remain attached to their substrate. They obtain nutrients through the flow of water across their cells, and they exchange gases by simple diffusion across their cell membranes. Pores called ostia draw water into the sponge and the water is subsequently circulated through the sponge by cells called choanocytes which have hair-like structures that move the water through the sponge.

The cnidarians include corals, sea anemones, jellyfish and hydras. These animals are always found in aquatic environments, ranging from fresh water to salt water. They do not have any dedicated respiratory organs; instead, every cell in their body can absorb oxygen from the surrounding water, and release waste gases to it. One key disadvantage of this feature is that cnidarians can die in environments where water is stagnant, as they deplete the water of its oxygen supply. Corals often form symbiosis with other organisms, particularly photosynthetic dinoflagellates. In this symbiosis, the coral provides shelter and the other organism provides nutrients to the coral, including oxygen.

The roundworms (Nematoda), flatworms (Platyhelminthes), and many other small invertebrate animals living in aquatic or otherwise wet habitats do not have a dedicated gas-exchange surface or circulatory system. They instead rely on diffusion of and  directly across their cuticle. The cuticle is the semi-permeable outermost layer of their bodies.

Other aquatic invertebrates such as most molluscs (Mollusca) and larger crustaceans (Crustacea) such as lobsters, have gills analogous to those of fish, which operate in a similar way.

Unlike the invertebrates groups mentioned so far, insects are usually terrestrial, and exchange gases across a moist surface in direct contact with the atmosphere, rather than in contact with surrounding water. The insect's exoskeleton is impermeable to gases, including water vapor, so they have a more specialised gas exchange system, requiring gases to be directly transported to the tissues via a complex network of tubes. This respiratory system is separated from their circulatory system. Gases enter and leave the body through openings called spiracles, located laterally along the thorax and abdomen. Similar to plants, insects are able to control the opening and closing of these spiracles, but instead of relying on turgor pressure, they rely on muscle contractions. These contractions result in an insect's abdomen being pumped in and out. The spiracles are connected to tubes called tracheae, which branch repeatedly and ramify into the insect's body. These branches terminate in specialised tracheole cells which provides a thin, moist surface for efficient gas exchange, directly with cells.

The other main group of terrestrial arthropod, the arachnids (spiders, scorpion, mites, and their relatives) typically perform gas exchange with a book lung.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Gas exchange


text:
Hortulus Animae

Hortulus Animae (Little Garden of the Soul, Seelengärtlein, Jardin des Âmes, Raj duszny) was the Latin title of a prayer book also available in German. It was very popular in the early sixteenth century, printed in many versions, also abroad in Lyons and Kraków.

History
An earlier well-known work of devotion and of moral instruction, richly illustrated with stories, was "Der Selen Würtzgart", first printed at Ulm in 1483. The meaning of the title is "Herb garden of the Soul", which is similar to later titles.

The first known edition of Hortulus Animae, dated 13 March 1498, was printed at Strasbourg by Wilhelm Schaffener of Ribeauvillé (Rappschwihr), followed by German versions appearing in 1501. Later editions contained woodcuts by the well-known engravers Hans Springinklee and Erhard Schön, with beautiful miniatures in some existing manuscript examples, like the one at Vienna (Cod. Bibl. Pal. Vindobonensis. 2706, 1907), which has been reproduced as facsimile by Friedrich Dornhöffer. In 1501/1502, Sebastian Brant from Strasbourg translated it into German.

Hortulus Animae polonice, a Polish version written by Biernat of Lublin, printed and published in 1513 by Florian Ungler in Kraków, was believed to be the first book printed in the Polish language (it is the second ). The last known copy was lost during World War II.

The work is mentioned briefly at the end of Edgar Allan Poe's short story "The Man of the Crowd."

title: Hortulus Animae


text:
Nitrite

The nitrite ion has the chemical formula. Nitrite (mostly sodium nitrite) is widely used throughout chemical and pharmaceutical industries. The nitrite anion is a pervasive intermediate in the nitrogen cycle in nature. The name nitrite also refers to organic compounds having the –ONO group, which are esters of nitrous acid.

Production
Sodium nitrite is made industrially by passing a mixture of nitrogen oxides into aqueous sodium hydroxide or sodium carbonate solution:
 * NO + NO2 + 2 NaOH -> 2 NaNO2 + H2O
 * NO + NO2 + Na2CO3  -> 2 NaNO2 +  CO2

The product is purified by recrystallization. Alkali metal nitrites are thermally stable up to and beyond their melting point (441 °C for KNO2). Ammonium nitrite can be made from dinitrogen trioxide, N2O3, which is formally the anhydride of nitrous acid:
 * 2 NH3 + H2O + N2O3 → 2 NH4NO2

Structure
The nitrite ion has a symmetrical structure (C2v symmetry), with both N–O bonds having equal length and a bond angle of about 115°. In valence bond theory, it is described as a resonance hybrid with equal contributions from two canonical forms that are mirror images of each other. In molecular orbital theory, there is a sigma bond between each oxygen atom and the nitrogen atom, and a delocalized pi bond made from the p orbitals on nitrogen and oxygen atoms which is perpendicular to the plane of the molecule. The negative charge of the ion is equally distributed on the two oxygen atoms. Both nitrogen and oxygen atoms carry a lone pair of electrons. Therefore, the nitrite ion is a Lewis base.

In the gas phase it exists predominantly as a trans-planar molecule.

Acid-base properties
Nitrite is the conjugate base of the weak acid nitrous acid:
 * HNO2 H+ + ;     pKa ≈ 3.3 at 18 °C

Nitrous acid is also highly volatile, tending to disproportionate:
 * 3 HNO2 (aq) H3O+ +  + 2 NO

This reaction is slow at 0 °C. Addition of acid to a solution of a nitrite in the presence of a reducing agent, such as iron(II), is a way to make nitric oxide (NO) in the laboratory.

Oxidation and reduction
The formal oxidation state of the nitrogen atom in nitrite is +3. This means that it can be either oxidized to oxidation states +4 and +5, or reduced to oxidation states as low as −3. Standard reduction potentials for reactions directly involving nitrous acid are shown in the table below:
 * {|class="wikitable"

!Half-reaction||E0 (V) The data can be extended to include products in lower oxidation states. For example:
 * + 3 H+ + 2 e− HNO2 + H2O|| +0.94
 * 2 HNO2 + 4 H+ + 4 e− H2N2O2 + 2 H2O||+0.86
 * N2O4 + 2 H+ + 2 e− 2 HNO2||+1.065
 * 2 HNO2+ 4 H+ + 4 e− N2O + 3 H2O||+1.29
 * }
 * N2O4 + 2 H+ + 2 e− 2 HNO2||+1.065
 * 2 HNO2+ 4 H+ + 4 e− N2O + 3 H2O||+1.29
 * }
 * }
 * H2N2O2 + 2 H+ + 2 e− N2 + 2 H2O;     E0 = +2.65 V

Oxidation reactions usually result in the formation of the nitrate ion, with nitrogen in oxidation state +5. For example, oxidation with permanganate ion can be used for quantitative analysis of nitrite (by titration):
 * 5 + 2  + 6 H+ → 5  + 2 Mn2+ + 3 H2O

The product of reduction reactions with nitrite ion are varied, depending on the reducing agent used and its strength. With sulfur dioxide, the products are NO and N2O; with tin(II) (Sn2+) the product is hyponitrous acid (H2N2O2); reduction all the way to ammonia (NH3) occurs with hydrogen sulfide. With the hydrazinium cation the product of nitrite reduction is hydrazoic acid (HN3), an instable and explosive compound:

 * HNO2 + → HN3 + H2O + H3O+

which can also further react with nitrite:
 * HNO2 + HN3 → N2O + N2 + H2O

This reaction is unusual in that it involves compounds with nitrogen in four different oxidation states.

Analysis of nitrite
Nitrite is detected and analyzed by the Griess Reaction, involving the formation of a deep red-colored azo dye upon treatment of a -containing sample with sulfanilic acid and naphthyl-1-amine in the presence of acid.

Coordination complexes
Nitrite is an ambidentate ligand and can form a wide variety of coordination complexes by binding to metal ions in several ways. Two examples are the red nitrito complex [Co(NH3)5(ONO)]2+ is metastable, isomerizing to the yellow nitro complex [Co(NH3)5(NO2)]2+. Nitrite is processed by several enzymes, all of which utilize coordination complexes.

Biochemistry

In nitrification, ammonium is converted to nitrite. Important species include Nitrosomonas. Other bacterial species such as Nitrobacter, are responsible for the oxidation of the nitrite into nitrate.

Nitrite can be reduced to nitric oxide or ammonia by many species of bacteria. Under hypoxic conditions, nitrite may release nitric oxide, which causes potent vasodilation. Several mechanisms for nitrite conversion to NO have been described, including enzymatic reduction by xanthine oxidoreductase, nitrite reductase, and NO synthase (NOS), as well as nonenzymatic acidic disproportionation reactions.

Chemical precursor
Azo dyes and other colorants are prepared by the process called diazotization, which requires nitrite.

Nitrite in food preservation and biochemistry
The addition of nitrites and nitrates to processed meats such as ham, bacon, and sausages reduces growth and toxin production of C. botulinum. Sodium nitrite is used to speed up the curing of meat and also impart an attractive colour. On the other hand a 2018 study by the British Meat Producers Association determined that legally permitted levels of nitrite have no effect on the growth of the Clostridium botulinum. In the U.S., meat cannot be labeled as "cured" without the addition of nitrite. In some countries, cured-meat products are manufactured without nitrate or nitrite, and without nitrite from vegetable source. Parma ham, produced without nitrite since 1993, was reported in 2018 to have caused no cases of botulism.

In mice, food rich in nitrites together with unsaturated fats can prevent hypertension, which is one explanation for the apparent health effect of the Mediterranean diet. Adding nitrites to meat has been shown to generate known carcinogens; the World Health Organization (WHO) advises that eating 50 g of nitrite processed meat a day would raise the risk of getting bowel cancer by 18% over a lifetime. However, 95% of the nitrite ingested in modern diets comes from bacterial conversion of nitrates naturally found in dietary vegetables. The recommended maximum limits by the World Health Organization in drinking water are 3 mg L−1 and 50 mg L−1 for nitrite and nitrate ions, respectively.

Curing of meat
In a reaction with the meat's myoglobin, nitrite gives the product a desirable pink-red "fresh" color, such as with corned beef. In the US, nitrite has been formally used since 1925. According to scientists working for the industry group American Meat Institute, this use of nitrite started in the Middle Ages. Historians and epidemiologists argue that the widespread use of nitrite in meat-curing is closely linked to the development of industrial meat-processing. French investigative journalist asserts that the meat industry chooses to cure its meats with nitrite even though it is established that this chemical gives rise to cancer-causing nitroso-compounds. Some traditional and artisanal producers avoid nitrites.

Antidote for cyanide poisoning
Nitrites in the form of sodium nitrite and amyl nitrite are components of many cyanide antidote kits. Both of these compounds bind to hemoglobin and oxidize the Fe2+ ions to Fe3+ ions forming methemoglobin. Methemoglobin in turn binds to cyanide (CN) creating cyanmethemoglobin, effectively removing cyanide from the complex IV of the electron transport chain (ETC) in mitochondria, which is the primary site of disruption caused by cyanide. Another mechanism by which nitrites are useful in treating cyanide toxicity is the generation of nitric oxide (NO). NO displaces the CN from the cytochrome c oxidase (ETC complex IV), making it available for methemoglobin to bind.

Organic nitrites

In organic chemistry, alkyl nitrites are esters of nitrous acid and contain the nitrosoxy functional group. Nitro compounds contain the C–NO2 group. Nitrites have the general formula RONO, where R is an aryl or alkyl group. Amyl nitrite and other alkyl nitrites have a vasodilating action and must be handled in the laboratory with caution. They are sometimes used in medicine for the treatment of heart diseases. A classic named reaction for the synthesis of alkyl nitrites is the Meyer synthesis in which alkyl halides react with metallic nitrites to a mixture to nitroalkanes and nitrites.

Safety
Nitrite salts can react with secondary amines to produce N-nitrosamines, which are suspected to cause stomach cancer. The World Health Organization (WHO) advises that each 50 g of processed meat eaten a day would raise the risk of getting bowel cancer by 18% over a lifetime; processed meat refers to meat that has been transformed through fermentation, nitrite curing, salting, smoking, or other processes to enhance flavor or improve preservation. The World Health Organization's review of more than 400 studies concluded, in 2015, that there was sufficient evidence that processed meats caused cancer, particularly colon cancer; the WHO's International Agency for Research on Cancer (IARC) classified processed meats as carcinogenic to humans (Group 1).

Nitrite (ingested) under conditions that result in endogenous nitrosation, specifically the production of nitrosamine, has been classified as Probably carcinogenic to humans (Group 2A) by the IARC.

title: Nitrite


text:
Talk:Spencer Tracy

Streamlining suggestion
Now that the whole article has undergone major revisions, I would suggest folding most, if not all, of the information in the first paragraph of the "Death and legacy section" into the last few paragraphs of the "Independent player; Stanley Kramer partnership (1956-1967)" section, if for no other reason than to remove, or at least reduce, duplicate information, such as his backing out of Cheyenne Autumn and The Cincinnati Kid, dying 17 days after finishing his scenes in Guess Who's Coming To Dinner, etc. — Preceding unsigned comment added by 74.100.63.148 (talk) 05:02, 5 January 2012 (UTC)

 * Hiya, I'm the one who wrote all the new stuff. And yes, I was still planning to change the "Death and legacy" section (I just thought it best to remove the "underconstruction" banner as soon as possible). I was still going to keep his death separate though, since the other section is titled "career". What I've been thinking is a section called "Health and death" coming after "Personal life", which would mention all his alcoholism, insomnia, dependence on pills, and then all his various health problems leading to his death. Then after that, a "Reception and legacy" section (which I also want to completely rewrite). What do you think of that? I know it is a bit awkward to briefly mention his death, then talk about his personal life, then go back to his death...but I do favour keeping "career" and "life" stuff separate. It's just annoying that they overlap for Tracy...And there is quite a bit to say about his death, so it definitely would clog up that section. Do people agree that it is best to cover his death separately, later on?

 * While I'm here, I'll also add (for interested people) that I am definitely planning to change some of the references so that it isn't almost entirely dependent on Curtis. I just wanted to get everything covered from that book first.

 * If anyone wants to make any comments about the changes I've made, please do. It's still very much a work in progress, and any help (even if it comes in the form of criticism) would be appreciated. --Lobo512 (talk) 07:43, 5 January 2012 (UTC)

Small part?
I would say that Tracy's part in "It's A Mad, Mad, Mad, Mad World" was anything but small. Did Tracy really film all of his appearances in just nine days? If so, were the nine days consecutive or not? — Preceding unsigned comment added by 173.51.124.210 (talk) 05:31, 22 January 2012 (UTC)
 * If you think about it, it's actually pretty small. It's an important part, but for the first two hours he only pops up a few times. This is the Curtis comment re nine days: "[the character backstory] wasn't much for him to go on, and with nine days of work ahead of him, Tracy made use of...." Sounds like it was 9 consecutive days. --Lobo512 (talk) 10:18, 22 January 2012 (UTC)

"Catholic-guilt"?
"Catholic-guilt"? I mean really now. No one can deny that Tracy was raised Catholic, and his sense of guilt over his son's Deafness is undeniable. But calling that "Catholic-guilt" as if the doctrine that God makes children deaf because of their parent's adultery were an actual and specifically Roman Catholic belief is editorial synthesis: hardly NPOV or even logically justifiable. We don't go around talking about people's "Catholic-hypocrisy" or "Catholic-charity" or calling people Catholic criminals because they are criminals and Catholics. I see from above attributing things to his Catholicism has been an NPOV issue above. Mere "guilt" is undeniable at quite sufficient for the lead. μηδείς (talk) 03:01, 26 May 2012 (UTC)
 * How is it making a generalisation about Catholicism? I was just trying to make clear that Spencer Tracy - this particular individual - felt guilt because of his religious beliefs. And that seemed the simplest way of saying it. It's also a handy way of slipping his religion into the lead, which I do feel is appropriate because he is (rightly or wrongly) quite strongly associated with his Catholicism. I can't see at all how this is suggesting ALL Catholics would feel guilt in that situation, you're reading into it way too much... -- Lobo (talk) 12:33, 26 May 2012 (UTC)
 * And I don't really appreciate you edit-warring by undoing my edit. You've brought this to the talk page, which was the right thing to do, but you could have let the discussion commence first...edit-warring just looks silly. -- Lobo (talk) 12:45, 26 May 2012 (UTC)
 * Does the objection continue or can I add it back? -- Lobo (talk) 18:33, 1 June 2012 (UTC)
 * No further comments about this so I'm re-adding it for now. -- Lobo (talk) 13:38, 4 June 2012 (UTC)

Sorry, I don't edit constantly and so I don't log in just to check one page's comments. You yourself have said that this is religious guilt on his part. That would be fine, I don't object to you saying "religious guilt." (actually, I'll vrevert my self to that.) The problem with calling it "Catholic-guilt" is that you are making it appear as if it is Catholic doctrine--which it most certainly is not--or unique to Catholics--which it most certainly is not.μηδείς (talk) 02:52, 5 June 2012 (UTC)

Anon editor
An anon editor has been removing cited materials with no reasons given for the deletions. Thank youRFD (talk) 16:06, 17 February 2015 (UTC)

Scotty Bowers rumours
Holanthony wants to include two paragraphs in this article about the Scotty Bowers rumours (in case anyone doesn't know, Bowers claims that he repeatedly slept with Tracy in the 1940s and 1950s). I don't think they warrant a mention, for the reasons outlines below. I've just been reverted by Holanthony again, even though we're in the process of discussing his additions on our talk pages, so it's obviously at the point where we need some more opinions. I'll copy and paste the stuff from our talk pages here:

Can I ask why you think the Bowers stuff should be included in the Tracy and Hepburn articles? It really doesn't deserve a mention. The Hepburn lesbian stuff has been around long enough to warrant a quick mention of it in her article, which I included, but it doesn't need detail (since the evidence for it is so slim). The Tracy rumours come solely from Bowers, though, and the fact that James Curtis (who did an incredible amount of detail for his biography) felt that there was no need to cover it in his book means the WP article shouldn't either. He only mentions Bowers, and the possibility of ST being bisexual, in the "Author's note" section at the end - and that is purely to dismiss his claims. For an example of how ridiculous Bowers is, William Mann interviewed him for his biography on Hepburn back in 2007. At this time, Bowers told Mann that Tracy was gay but said nothing about Kate. Then a few years later and he's claiming that he hooked KH up with 150 women. If this was true, surely he would have told Mann, and Mann would include it in the book (since he argues that KH was probably gay)? Obvious proof that Bowers is a liar. It's such a trashy book, and we're meant to use good quality sources. If the same sort of lame rumours, from the same sort of source, were included in a BLP (say, the ones about Hugh Jackman) they'd be removed instantly. I think the same standards should apply for dead people. -- Loeba (talk) 19:36, 22 February 2015 (UTC)
 * Wikipedia does not take personal opinions and perceived personal offense into account. Bowers' claims have been met with mixed responses, some which support your criticism, while others support Bowers. This I have mentioned in a supporting note. Still, Bowers' claims have left a huge impact and this should be addressed to some manner. Also, the claims forwarded by Bowers have not been substantially refuted by other than subjective opinions. User:Holanthony (talk)
 * It's not that I think it's "offensive", I just think it's ridiculous to include such a poor source - especially in the level of detail that you included. I appreciate that you showed both sides of the argument, but ultimately it's just giving way too much weight to a poor source. A general guideline for WP is to follow what other third party sources do; the Hepburn rumours usually are mentioned to some degree in books about her, which is why I think it's appropriate to give that some coverage in her article. Since the Tracy rumours began there's been an excellent biography written about him, and the author felt that the rumours were too insubstantial to mention. So that's why I don't think our article should say anything about them either...but if we do, it definitely shouldn't be more than a couple of sentences. -- Loeba (talk) 19:54, 22 February 2015 (UTC)

Holanthony, if you really refuse to step down on this (even though it's beyond me why you think this information is appropriate) then can we at least cut it down to a couple of sentences? Something like "In the 21st century, a man named Scotty Bowers claimed that he was Tracy's casual lover for many years. James Curtis refuted these claims as "unverifiable", and said there was no evidence of Bowers in any of Tracy's personal documents." That is literally ALL that needs to be said on this issue. Third party opinions wanted, please, if anyone reads this. -- Loeba (talk) 20:03, 22 February 2015 (UTC)
 * Also, I just looked at that David Thomson article and your text about it was misrepresentative. Thompson doesn't say that Bowers's book is "the fruit of six years' serious work, and not to be taken lightly", as you wrote, he's saying that Curtis's research is not to be taken lightly. So he's not fully supporting Bowers at all. -- Loeba (talk) 20:19, 22 February 2015 (UTC)

Ok, point in question made. I'm not going to be impossible about this so I've revised the text and condensed it to only mention the necessities without quoting passages from the book. I've also mentioned Curtis' objection. Hopefully we can put the matter to rest now.User:Holanthony (talk)

I tried to include a single line about Bowers’ claim, which was immediately deleted. BigJake54 (talk) 20:52, 15 June 2019 (UTC)

Mann Biography & Bowers
Ok, taking this to the talk page now as Blofeld has deleted not only my latest input but also the passage added by Loeba  with the motivation that it was not "encyclopedic" but has made to effort to redit the passage or suggest how it be done to fit their liking. This time I have moved away from only relying on Bowers' to rather put more weight on Mann's biography (which predates Bowers' book by six years). Mann in fact mentions Bowers' and confirms the gay rumours of both Tracy and Hepburn. I also mentioned that Gore Vidal has confirmed these reports. Why this this problematic? If several legitimate sources claim the same thing, ought it not bring credence to the understanding that these rumours should be addressed in the Wikipedia article?

Here is the text I tried to insert:

In 2012, a man named Scotty Bowers claimed that he had been Tracy's lover in the 1940s and 1950s. Biographer James Curtis has disputed these claims as "unverifiable", and said there was no evidence of Bowers in any of Tracy's personal documents. Nevertheless, Bowers' claims were vouched for by Gore Vidal. In fact, William J. Mann makes mention of Bower's in his 2006 biography of Hepburn. Mann suggests Tracy was "fluid" in his sexuality, describing his close friendship with playboy Tim Durant, before recounting his dalliances with a Hollywood “male madam” named Scotty [Bowers]. While not denying the chemistry between Tracy and Hepburn, Mann questions the intimacy of their relationship, citing the fact that they never lived together and paints Hepburn's role as more similar to a caretaker than lover of the deeply alcoholic (and married) Tracy. Moreover, Mann contends that Hepburn concocted their supposed romance after Tracy had died.

 * The fact that Mann mentions Bowers doesn't "confirm" anything. He was the first one to publish the Bowers stuff, but that's what James Curtis was responding to in 2011 (Bowers' own book hadn't been published at that point) and he called bullshit. Mann's speculations about the Hepburn-Tracy relationship are also based on nothing substantial. He had no access to either of their personal documents, whereas Curtis did and he presents the relationship as a romantic one (publishing letters, diary entries (brief, but still telling), records of international phone calls, and comments from people who saw them together along the way). ST and KH weren't together much in the 1950s, and it's likely that the relationship was pretty platonic towards the end - but they lived together and were devoted to one another at that point, as several witnesses confirmed. The possibility of them being bisexual isn't insulting, but the suggestion that their relationship was a lie is another matter.
 * I wonder if Mann still believed Bowers when, five years later, he went on to publish a load of stuff about Kate being with women that he had neglected to tell him...As for Gore Vidal, I don't believe he knew either Kate or Spencer so he has no business confirming this stuff. -- Loeba (talk) 18:13, 26 February 2015 (UTC)

removing referenced material
An Ip editor has twice now removed referenced material as hearsay and unsupportable. https://en.wikipedia.org/w/index.php?title=Spencer_Tracy&diff=649851129&oldid=649697610 Obviously the material is supproted, the IP is invited to provide evidence the references have been falsified or there is a competing interpretation. μηδείς (talk) 20:14, 4 March 2015 (UTC)

Duplication of death year
His death in 1967 is mentioned twice in the lead and three times in the infobox (or four, if you count the years active parameter). This strikes me as unnecessary. DrKay (talk) 17:31, 6 May 2016 (UTC)
 * The marriage template used here is supposed to give the end date of the marriage and the reason for the end of the marriage. For people such as Spencer Tracy and Abraham Lincoln, the end date of the marriage is the date of death of the person. For others, it may be divorce, annulment, the death of the spouse, etc. For that reason, using the date of death in the template and the reason=death really isn't duplicative. 32.218.47.115 (talk) 18:10, 6 May 2016 (UTC)
 * The template does not say that the marriage ended in 1967. It says he died in 1967. The wording "until his death" would indicate the end of the marriage but the wording "his death" is not explanatory. DrKay (talk) 18:59, 6 May 2016 (UTC)
 * Then change the wording, rather than throwing the baby out with the bathwater. 32.218.47.115 (talk) 19:16, 6 May 2016 (UTC)

Possible word error
Someone wrote to Wikimedia claiming that the word "clump" sourced to page 402 of "Hepburn, Katharine (1991). Me: Stories of My Life. Alfred A. Knopf. ISBN 0-679-40051-6." should really be "thump".

I checked Google books but while some pages are shown page 402 is not included in my preview. Could someone who has access to the book confirm whether the current wording is correct or if it should be changed?-- S Philbrick (Talk)  20:45, 16 March 2017 (UTC)
 * Pinging who added the word, although they aren't all that active recently.-- S Philbrick  (Talk)  22:09, 16 March 2017 (UTC)

 * Apologies for the delay. My books are in storage right now so I can't check, but I'm pretty sure I must have copied it correctly...especially as the word comes up twice. Hepburn did use unusual words sometimes.  Loeba (talk) 13:16, 20 July 2017 (UTC)
 * Good news. A new search uncovered this, confirming "clump". -- S Philbrick (Talk)  13:20, 20 July 2017 (UTC)

Judy Garland
This is mentioned in the Judy Garland article but isn't in here anywhere: "She was raped by Spencer Tracy at the age of fourteen, when she was unable to legally consent to the affair." Perhaps we can discuss adding it? — Preceding unsigned comment added by Flymat (talk • contribs) 18:39, 6 March 2018 (UTC)
 * Neither source says rape and neither says she was below the age of consent. This is original research by synthesis unless we find a source that actually states it explicitly. DrKay (talk) 22:03, 6 March 2018 (UTC)

Homosexuality
According to Vanity Fair, he had sex with men for money - that is, he paid for the sex.

https://www.vanityfair.com/hollywood/2018/07/scotty-and-the-secret-history-of-hollywood-cary-grant-katharine-hepburn

That's a reliable source, as is NPR and the many other sources reporting on this recently and in the past. Why isn't it mentioned in his article? The most effectual Bob Cat (talk) 13:04, 4 August 2018 (UTC)
 * This sort of content should always be balanced against sources that say it's improbable: "James Curtis ... dismisses Mr. Mann's account of Hepburn's and Tracy's sexuality, characterizing Mr. Bowers as unreliable. 'Bowers is full of glib stories and revelations, all cheerfully unverifiable'." "Curtis went on to say: 'There is no hint of homosexual activity in the Tracy papers nor in anything I have seen or learned elsewhere during the course of researching this book.'" DrKay (talk) 14:41, 4 August 2018 (UTC)

Missing film in filmography
Please add 1957 The Actress to his filmography Gursel Ali (talk) 10:08, 29 May 2022 (UTC)

title: Talk:Spencer Tracy


text: Talk:Quantitative marketing research

title: Talk:Quantitative marketing research


text:
User:Diderot

Denis Diderot était le redacteur d'une des plus importantes encyclopédies de l'histoire, connue le plus souvent sous le nom "L'Encyclopédie de Diderot." Étant surpris que personne n'a pris ce nom d'usager, moi, je m'en charge, bien que je sois lexicographe, traducteur et informaticien par profession et non pas encyclopédiste. Quelqu'un doit travailler sous ce grand nom si Wikipédia va vraiment devenir l'héritier de la tradition encyclopédiste révolutionaire. J'ai toujours resenti une très grande amour pour les oeuvres de référence et j'ai lu Wikipédia pendant longtemps avant de contribuer. Je suis canadien d'origine, longtemps resté aux États-Unis avant de m'installer à Bruxelles.

What? You don't speak French? Tsk, tsk... Well, I suppose I ought to say something in English, since it's the only language I feel really comfortable writing in. I'm an expatriated Canuck married to a Californian beach babe. Just like Wayne Gretzky. Only, he lives in LA and owns a hockey team. I just live in Brussels and own an iMac.

In case it's unclear, I am neither this guy nor this guy.

fr:Utilisateur:Diderot iu:User:& nl:Gebruiker:Diderot ru: Участник:Дидро zh:User:&

title: User:Diderot


text:
User:Olpus

Origin of my nickname
"Olpus" doesn't mean something particularly. I punched the keys of my computer's keyboard randomly when I was inserting my nickname in a videogame's best score list. And the result was "olpus". I liked that, so it's a long time that I use that username. Some times ago I realized that the word "olpus" is used by professional photographers as an abbreviation of Olympus camera brand.

Links

 * My page on MySpace.
 * My page on Facebook.
 * My page on Twitter.
 * The page of my experimental noise band.

title: User:Olpus


text:
Famous

Famous is a word usually meaning notability or celebrity. Famous may refer to:

Companies

 * Famous Brands, a South African restaurant franchisor
 * Famous Footwear, an American retail store chain
 * Famous Music, the music publishing division of Paramount Pictures
 * Famous Studios, the animation division of Paramount Pictures from 1942 to 1967

Music

 * Famous?, an album by JME
 * Famous (Marques Houston album), 2013
 * Famous (Puddle of Mudd album)
 * "Famous" (Puddle of Mudd song), 2007
 * Famous (Super Deluxe album), 1995
 * Famous (Taemin EP), 2019
 * "Famous" (Charli XCX song), 2015
 * "Famous" (French Montana song), 2017
 * "Famous" (Kanye West song), 2016
 * "Famous" (Mason Ramsey song), 2018
 * "Famous" (Nathan Sykes song), 2016
 * "Famous" (Play song), 2010
 * "Famous" (Scouting for Girls song)
 * "Famous" (Tinchy Stryder song), 2010
 * "Famous", a song by 21 Savage from his album Issa Album
 * "Famous", a song by Inna from her album Party Never Ends

Other uses

 * Charles W. Famous (1875–1938), American politician and physician
 * Lisa Picard Is Famous, also known as Famous, a 2000 film
 * Famous, Missouri, a community in the United States

title: Famous


text:
Poenit

Poenit may refer to:
 * Poenitentiaria or Apostolic Penitentiary
 * Phut

title: Poenit


text:
VIP (disambiguation)

A VIP is a very important person.

VIP or V.I.P. may also refer to:

Entertainment

 * V.I.P. (comedian), Indian television comedian
 * VIP (magazine), an Irish celebrity lifestyle fashion magazine
 * VIP, a video brand formerly used by Japanese adult video company Atlas21
 * V.I.P. (talk show), a 1973–1983 Canadian television talk show
 * V.I.P. (American TV series), a 1998–2002 American television series starring Pamela Anderson
 * VIP (South Korean TV series), a 2019 South Korean television series
 * VIP Magazin, a Moldovan celebrity lifestyle magazine

Film

 * Very Important Person (film), 1961 British film
 * The V.I.P.s (film), 1963 film
 * VIP my Brother Superman, 1968 Italian animation film
 * V.I.P. (1991 film), Polish film by Juliusz Machulski
 * V. I. P. (1997 film), Indian Tamil film
 * VIPs (film), 2010 Brazilian film
 * Velaiilla Pattadhari, 2014 film also known as VIP
 * V.I.P. (2017 film), South Korean film

Music

 * V.I.P. (Hungarian band), defunct pop boy group
 * The V.I.P.'s (band), English band of the 1960s
 * Voices in Public, Canadian boy group
 * VVIP (hip hop group) Ghanaian hiplife band once known as VIP
 * V.I.P. (album), 2000 album by Jungle Brothers, or the title track
 * "V.I.P." (Bro'Sis song) (2003)
 * "V.I.P" (Ice Prince song) (2013)
 * "V.I.P" (Sid song) (2013)
 * "VIP" (Aya Nakamura song) (2022)
 * V.I.P., subsidiary label of Motown Records
 * "VIP", song by Kesha from Animal
 * The V.I.P. (The Vanilla Ice Posse), the rapper's DJs and backup dancers
 * Victory in Praise Music and Arts Seminar Mass Choir, an organization founded by John P. Kee
 * "V.I.P.", song by Françoise Hardy

Science

 * Vasoactive intestinal peptide, a peptide hormone
 * Ventral intraparietal sulcus in the lateral parietal lobe of the human brain

Telecommunications and Internet telephony

 * Vip mobile, Serbian mobile network operator
 * Virtual IP address

Other uses

 * Plymouth VIP, a luxury version of the Plymouth Fury, 1966-1969
 * Vacuum insulated panel, a form of thermal insulation consisting of a nearly gas-tight enclosure surrounding a rigid core, from which the air has been evacuated
 * Variable Information Printing, a form of on-demand printing
 * VimpelCom's stock symbol
 * VIP Ecuador, an Ecuadorian airline
 * VIP Industries, a luggage manufacturer based in India
 * VIP's (restaurant), an American restaurant chain
 * Virgil Partch, a cartoonist who signed his work Vip
 * Virgin Islands Party, a political party in the British Virgin Islands
 * Virology Science and Technology Institute of the Philippines, also known as the Virology Institute of the Philippines (VIP)
 * Vision Inspired by the People, a political party in Belize
 * Visually impaired person

title: VIP (disambiguation)


text:
Holy Cross Sermons

The Holy Cross Sermons (Kazania świętokrzyskie) are the oldest extant prose text in the Polish language, dating probably from the late 13th or early 14th century. The documents are named after the place where they were originally housed – the Holy Cross Monastery (pl) in Poland's Holy Cross Mountains (Polish: Góry Świętokrzyskie). They were discovered in striped parchment pieces in 1890 by Aleksander Brückner, in the binding of a Latin language codex, which contained the Acts of the Apostles and the Apocalypse. The sermons were first published in 1891, in a "Philological Works" ("Prace Filologiczne") magazine. In 1934, facsimiles of the text were published by the Polish Academy of Learning, and in 2009, new, full edition of the sermons was issued, prepared by professor Paweł Stępień.

History
Even though Aleksander Brückner claimed that the text was originally housed at the Holy Cross Monastery, this hypothesis has been criticized by some scholars. According to historian Władysław Semkowicz, the codex, already strengthened with parchment stripes, was delivered to a Benedictine monastery at Leżajsk, around 1459.

The Leżajsk monastery, however, was not the location where the sermons were written. Language analysis carried out by Polish experts proved that the text was probably written in a monastery in Miechów, which was famous for its sermons and library, and which cooperated with the Leżajsk monastery. On the other hand, if sermons were written in the 13th century, then their Miechów origins are dubious. At that time, this monastery was made of monks of Czech and German origin, who either did not speak Polish, or spoke it poorly, and who were unable to write down the complicated text.

Some time in the 15th century, the sermons were cut into strips, which were used to strengthen the binding of a Latin language codex. Most likely, other parts of the sermons were used in bindings of other books. This practice was common at the time, as parchment was both durable and expensive, so publications regarded as unnecessary or unimportant were frequently used to strengthen other, more precious books.

Aleksander Brückner discovered the sermons on March 25, 1890, at the Imperial Public Library in St. Petersburg, Russian Empire. He was studying an ancient Latin codex, which had belonged to the Warsaw University library, and was confiscated by the Russians after the November Uprising (1831). In the binding of the book, Brückner to his surprise found eighteen long strips. After putting them together, it turned out that they contained one whole, and five incomplete sermons.

They were brought back to Poland in 1925. During World War II, the Holy Cross Sermons were taken to Canada for safekeeping. They are now preserved at the National Library in Warsaw (#8001), and their photocopy may be seen at The Digital National Library Polona (See electronic version of the Holy Cross Sermons). From May 2024, the manuscript is presented at a permanent exhibition in the Palace of the Commonwealth.

Description
The sermons, on the occasions of Church holy days, comprise fragments of five texts and one complete sermon (for St. Catherine's Day). Written on parchment, they had been cut into thin strips and used to reinforce the binding of a 15th-century Latin manuscript. The fifteen strips, put together by Bruckner, make one sheet (117 × 173 mm), and the remaining three strips make the bottom of a second sheet.

Linguistically, the Holy Cross Sermons reflect an older stage of the language than the 14th century, the manuscript being a copy of original sermons composed some time from the end of the 13th century. They manifest a variety of linguistic archaisms, for instance:

1) Hard-stem declension of the pronoun *tъnъ 'this one': Nom. sg. ten, Gen. sg. togo, Dat. sg. tomu;

2) Aorist and Imperfect:

- 1 sg. aor. widziech (cf. Lat. perf. vidi) < PSl. *viděti 'to see, to look', *viděxъ 'I saw, I looked (at); I have seen, I have looked (at)';

- 3 sg. aor. postawi (cf. Lat. perf. posuit) < PSl. *postaviti 'to place', *postavi 'he/she/it placed, has placed';

- 3 pl. aor. pośpieszychą się (cf. Lat. perf. venerunt) < PSl. *pospěšiti 'to go, to go somewhere', *pospěšixǫ 'they went, they went somewhere, they went out';

- 3 sg. impf. biesze (cf. Lat. impf. erat) < PSl. *byti 'to be', *běaše 'he/she/it was';

- 3 sg. impf. siedziesze (cf. Lat. impf. sedebat) < PSl. *sěděti 'to sit', *sěděaše 'he/she/it sat, was sitting'.

Contents
The strips contain a whole sermon for St. Catherine's Day (November 25), and parts of sermons for the following days:
 * Michaelmas (September 29),
 * Saint Nicholas Day (December 6),
 * Christmas (December 24),
 * Epiphany (called in Poland Three Kings’ Day, January 6),
 * Feast of the Purification of the Virgin (February 2).

title: Holy Cross Sermons