Jenny Boucard

The Nouvelles annales de mathématiques are a French mathematical journal, published between 1842 and 1927, for candidates to polytechnic and normal schools, then to licence and agrégation applicants. In this paper, we will rely on a systematic analysis of number theory content -a mathematical field that is virtually absent from French education programs during the period under consideration here -in the Nouvelles annales. Our goal is twofold: we will show what forms takes number theory through this specific media, and we will see how a teaching mathematical journal as the Nouvelles annales de mathématiques operates through the arithmetic focal. For this, we will rely on the actors involved (editors, authors, readers), on the various forms of texts published, on the thematic studied as well as the arithmetical practices and discourse mobilized.

I -The Nouvelles Annales de Mathématiques as an observation point to study how number theory was diffused in a teaching sphere

With the rapid development of an « intermediate press » [START_REF] Ortiz | El rol de las revistas matematicas intermedias en el establecimiento de contactos entre las comunidades matematicas de Francia y Espana en elhacia fines del siglo XIX[END_REF] in the second half of the nineteenth century, the mathematical publishing landscape was reconfigured 1 . These intermediate journals, explicitly intended for a readership of teachers and students, offered mathematical content that was related to education or that was considered as « elementary », and therefore accessible to the target readership. It is therefore important to take into account these media in the field of the history of mathematics education.

The aim of this paper is to use a systematic analysis of the arithmetical content published in a French journal of mathematics for teachers and students, the Nouvelles annales de mathématiques (NAM), in order to identify the various forms taken by number theory in this specific context. The NAM is here used as a valuable observation point in order to study the means of diffusion of number theory in a milieu linked to mathematical teaching and to identify the many facets linked to teaching practices in this specific case.

The NAM was published between 1842 and 1927, in the form of 84 volumes with approximately 5000 contributions by 1835 authors. It thus constitues a relevant way to analyze the mathematical content for a intermediate public over a relatively long time 2 . Its explicit target readership was students who were preparing for the admission examination of the École Polytechnique and the École normale supérieure. From 1888, the journal was also dedicated to students studying for licence and agrégation 3 . The NAM had a unique position in the French publishing landscape for the first 25 years of its existence. However, from 1877, the growth of the number of students spurred the creation of other periodicals with the same aims, such as the Journal des mathématiques élémentaires. By explicitly including a university audience and with the coexistence of other mathematical 1 More generally, the number of periodicals containing mathematics has grown significantly since the 18 th century. Since the 1990's, several mathematical works on history of mathematics have been devoted to the study of journals or have taken into account the specific form of mathematical journals in the analysis of a mathematical topic: among others, see (Ausejo & Hormigón, 1993 ;[START_REF] Despeaux | The development of a publication community : Nineteenth-century mathematics in British scientific journals[END_REF][START_REF] Verdier | Le Journal de Liouville et la presse de son temps : une entreprise d'édition et de circulation des mathématiques au XIX e siècle (1824 -1885[END_REF][START_REF] Romera-Lebret | La nouvelle géométrie du triangle à la fin du XIXe siècle: des revues mathématiques intermédiaires aux ouvrages d'enseignement[END_REF][START_REF] Boucard | Circulations mathématiques et congruences dans les périodiques de la première moitié du XIXe siècle[END_REF][START_REF] Morel | Le microcosme de la géométrie souterraine : échanges et transmissions en mathématiques pratiques[END_REF]. A project whose goal is the study of the circulation of mathematics, especially through journals, over a long period of time is currently being lead by Hélène Gispert, Philippe Nabonnand and Jeanne Peiffer: https://cirmath.hypotheses.org. 2 In this study, I have used the database dedicated to the NAM and lead by Hélène Gispert, Philippe Nabonnand and Laurent Rollet : http://nouvelles-annales-poincare.univ-lorraine.fr. 3 Licence is one of the degree from the Université in France and agrégation is a French teacher recruitment competition. journals for teaching, the mathematical content of the NAM changed considerably during its publishing period [START_REF] Nabonnand | Un journal pour les mathématiques spéciales : les Nouvelles annales de mathématiques (1842-1927[END_REF].

Number theory represents an interesting case because of its very marginal position in French teaching. If the NAM is known not to be limited to the curriculum for mathematics in French schools, it is interesting to see how a field as number theory is treated in a mathematical journal for teaching. As one of the first editors of the journal, Olry Terquem, wrote to his friend Eugène Catalan in 1849, it was important to give « clear solutions, at the scope, at the level of the students »4 . We will analyse here the multiple ways in which number theory appears « at the level of the students ».

II -Number theory in

France in the nineteenth century, from the Académie des sciences to educational curricula

At the Academy

Traditionally, the history of mathematics has viewed number theory in nineteenth-century France as weak. This image was also maintained by the actors themselves on many occasions. For example, Charles-Ange Laisant regretted the situation of number theory in France when he presented the recently-published book, Théorie des nombres, by Édouard Lucas (1891) : « [Lucas] was in correspondence with the most illustrious representatives of this science [number theory], so French in origin, and unfortunately so neglected in France today » (Laisant, 1892, p. 37) 5 . It has, however, been shown that these discourses reflect only a very partial reality [START_REF] Goldstein | Sur la question des méthodes quantitatives en histoire des mathématiques : le cas de la théorie des nombres en France (1870-1914)[END_REF]Goldstein & al., 2007).

Before considering number theory in the NAM, it is therefore important to give a brief overview of the history of number theory in the nineteenth century (Boucard, 2015a). Around 1800, two books [START_REF] Legendre | Essai sur la théorie des nombres[END_REF][START_REF] Gauss | Disquisitiones Arithmeticae[END_REF] dedicated to number theory were published. Adrien-Marie Legendre's treatise was a synthesis of results conjectured and/or proved by Pierre de Fermat, Leonhard Euler or Joseph-Louis Lagrange and is focused on indeterminate analysis. In Carl Friedrich Gauss' Disquisitiones arithmeticae (1801), number theory concerned integers and eventually rationals. The book is organized on two main arithmetical objects : congruences and forms.

In the first quarter of the nineteenth century, the algebraic contents of Gauss' work -the algebraic resolution of binomial equations x n =1 was considered, especially in algebra texts. Research devoted to analysis and/or related to physical problems are placed on the center stage, particularly in France, and number theory is often described as uninspiring6 . Between 1825 and the 1860's, a research domain, called Arithmetic Algebraic Analysis in (Goldstein & Schappacher, 2007a), was then developed by an international network of scholars. It linked questions in number theory, algebraic equations and analysis by developing some of Gauss' results. Its objects of research were multiples, including congruences, ideal numbers, formal series, forms, elliptic functions, etc. At the end of the nineteenth century, number theory was more or less prestigious and stable depending on the different mathematical milieux. It was organized in several main sub-domains including elementary number theory, arithmetic theory of forms, theory of ideal numbers and generalisations, algebraic number theory, and analytical number theory [START_REF] Goldstein | Sur la question des méthodes quantitatives en histoire des mathématiques : le cas de la théorie des nombres en France (1870-1914)[END_REF]Goldstein & Schappacher, 2007b). If nineteenth-century French mathematicians did not study the number-theoretic topics that were later considered to be fundamental in the twentieth century-such as algebraic number theory-they were not unproductive in number theory as a whole. For example, in the first half of the nineteenth century, the numbers of French and German texts published in connection with the congruences are very close, even if the issues studied were not the same [START_REF] Boucard | Résidus et congruences de 1750 à 1850 : une diversité de pratiques entre algèbre et théorie des nombres[END_REF].

In education

In nineteenth-century France, teaching programs for the classes de mathématiques élémentaires and for the classes de mathématiques spéciales -corresponding to the classes préparatoires -, were relatively homogeneous and oriented by the Polytechnic School syllabus. Number theory was then virtually nonexistent in these syllabus. While French teaching was deeply reformed from 1840 to 1914, the arithmetical content of the various curricula was very stable and was reduced to some elementary subjects, distant from the ones mentioned above, and included in algebra textbooks as [START_REF] Choquet | Traité élémentaire d'algèbre[END_REF]. From 1843, number theory was reduced to notions about prime numbers, properties of divisibility, decimal fractions and periodic decimal fractions for the mathématiques élémentaires and to continued fractions and resolution of indeterminate equations of the first degree for the mathématiques spéciales [START_REF] Belhoste | Les sciences dans l'enseignement secondaire français[END_REF]. The situation was quite similar for the program of the agrégation of mathematics, where we can find elementary notions about prime numbers and divisibility (in 1895, Fermat's and Wilson's theorems have to be known by the candidates) and themes within algebra and number theory (still in 1895, binomial equations, primitive roots and regular polygons were part of the subjects of the lessons). The situation was for example very different in German states: lessons on number theory were given there in several universities (at least in Berlin and Königsberg) from the 1830's and Jacobi, for exemple, dedicated a whole course on number theory, including cyclotomy, reciprocity laws and quadratics forms in 1836-1837 (Jacobi & al., 2007). Nevertheless, we can note that some courses in number theory were regularly and locally given in French faculties, mostly from the end of the nineteenth century. Among geometers providing lessons in connection with number theory earlier, Joseph Liouville devotes several lessons from his course on definite integrals at the College de France to recent research of number theory [START_REF] Belhoste | Joseph Liouville et le Collège de France[END_REF] and Victor-Amédée Lebesgue taught lessons on Gauss's Disquisitiones arithmeticae at the Sciences Faculty in Bordeaux in the 1860's. He also had a project to publish a treatise of number theory in three volumes, which was repeatedly announced in the NAM and that was defended by the academicians of the Geometry section to the Minister of the Public Instruction in 1864.

If there was a contrast in France between the essential transformations mentioned above in "academic" number theory during our period of investigation and the stability of the content that was taught in France, several actors encouraged the dissemination of number theory and its integration in elementary treatises, alongside the aforementioned university courses. Thus, Louis Poinsot published a paper on number theory in 1845 containing several demonstrations of basic arithmetical results in the Journal de mathématiques pures et appliquées. The long introduction of this memoire precisely advocated for the need to integrate the theory of numbers in elementary books : « From all these reflections, and a host of others I might add, I conclude therefore that the principles of algebra and number theory should be united together in our elementary treatises, as they are inseparable from the nature of these two sciences » (Poinsot, 1845, p. 11) 7 . This introduction had been already published in 1841 in the report of the Académie des sciences, at a time when Poinsot had just been appointed to the Conseil de l'instruction publique and was responsible for the texts on mathematics education. We will repeatedly find the will to disseminate number theory widely in the NAM III -Number theory in the Nouvelles Annales de Mathématiques : actors and content-related education ?

After a systematic analysis of the NAM, I identified 876 entries by 236 contributors with numbertheoretic content 8 . In this study, I took a broad interpretation of "text" that could mean an article, a question 9 , an answer, a review of a publication, a comment on exams and teaching programs or an extract of a letter. In table 1, the number-theoretical content compared to the total number of items published in the NAM is indicated for three forms of texts : articles, questions and answers. We can see that the proportion of number-theoretical articles for the whole period is less than 12% but that the number of questions and answers published grows intensively between 1870 and 1890.

Table 2 presents the distribution of the professional categories of the authors. Teachers at all levels represent a dominant majority of the authors, and students constitute the second largest category represented in the NAM If we compare these findings to general results about the NAM [START_REF] Nabonnand | Un journal pour les mathématiques spéciales : les Nouvelles annales de mathématiques (1842-1927[END_REF], it seems that the percentage of teachers is higher on average in the case of number theory. As in the general case, several authors were engineers or were in the military, knowing that among them, some also taught, in military school for example. From these quantitative data, the ideal audience wished for the NAM seems to have coincided with the reality, at least for the authors. Among the 236 contributors, 14 authors published more than ten times in the NAM Their profiles are quite diverse: for example, Savino Realis was an engineer in Torino, Eugène Lionnet taught in secondary school, Lucas was a high school teacher and recognized for his number-theoretic contributions, Lebesgue obtained a post in university and became correspondant at the Academy of science in 1847, especially thanks to his work in number theory, Raoul Bricard taught at Polytechnic then at the Conservatoire national des arts et des métiers, and Ernesto Césaro and Angelo Genocchi taught in universities in Italy. We also can notice that among these principal authors, four of them were at some point editors of the NAM : Laisant, Bricard, Eugène Prouhet and Terquem 10 . However, these quantitative data are limited : for example, Terquem, who only published ten times in the NAM, had a somewhat important role in the diffusion of number theory in the journal as we will see below. 8 Identifying what fall into « number theory » is problematic, specially in the nineteenth century, when the classifications proposed in journals and definitions given by the authors are very unstable (Goldstein, 1999, p. 194-199 ;Boucard, 2015b, p. 513-514). Here, I chose to make a wide use of the classifications contained in the NAM and in the Jahrbuch über die Fortschritte der Mathematik. For example, if a subject, like « indeterminate equations » is classified at some point in one of the topic « arithmetic » or « number theory », I consider it as part of number theory for the whole period under consideration here. 9 Many mathematical journals included a section on « Questions and answers ». For a study of this specific category in British journals, see [START_REF] Despeaux | Mathematical questions: a convergence of mathematical practices in British journals of the eighteenth and nineteenth centuries[END_REF]. 10 I refer to [START_REF] Nabonnand | Un journal pour les mathématiques spéciales : les Nouvelles annales de mathématiques (1842-1927[END_REF] for the successive compositions of the editorial board of the NAM. Table 3 contains data concerning the topics of number theory published in the NAM, indicated by the percentage of each category compared to the whole number-theoretical content. We can see that the main subjects studied were indeterminate analysis and divisibility. These were subjects that were close to teaching curricula or that could be treated with algebraic methods, that is to say mathematical expertise expected from the students. But other types, as residues, congruences and higher arithmetic, or arithmetic linked with geometry or recreational arithmetic (such as articles and questions about mathematical chessboards) correspond to number theory that was developed in other places, such as at the Academy or the Association française pour l'avancement des sciences. As for the articles, questions concerned a wide range of subjects such as higher arithmetic or congruences were more regularly addressed in articles than in questions. The questions about indeterminate equations and divisibility can be interpreted as a training for students as they are part of the teaching program or their resolution implies the use of algebraic tools. With the analysis of the category "Answer", we also find around forty new contributors whose answers to one or more questions have not been published but whose names are indicated in the journal. Most of them are high school students and it seems to show a certain emulation inside some given school. For example, three students from the Lycée Saint-Louis and whose mathematical teacher was Charles Briot answered arithmetical questions between 1862 and 1865.

Table 3. Repartition of all the arithmetical texts, the articles and the questions according to the thematics (in %). Tables 4 shows, from four examples, that the different topics were not present in a homogeneous way during the whole period of the journal's existence. Here I used the periodisation proposed in [START_REF] Nabonnand | Un journal pour les mathématiques spéciales : les Nouvelles annales de mathématiques (1842-1927[END_REF]) that was conceived from the consideration of the material history of the journal, the evolution of the targeted audience, the teaching curricula and the editorial landscape. The first period corresponds to the launching of the journal, the second, to the time when the journal seemed to have achieved its goals in terms of readership and contents. During the third period, the intended audience seemed to be more and more linked to university sphere. During the first and third periods, it is interesting to note that at least one of the editors -Terquem from 1842 to 1862, Laisant from 1896 to 1920 and Bricard from 1904 to 1927 -were scholars who published regularly -at least ten times -about number theory. If indeterminate analysis constituted the dominant topic studied during the whole period, it represented nearly half of the published entries during the second period, especially because of the increasing number of questions and answers. On the contrary, subjects as congruences, cyclotomy or algebraic number theory, have a more important place in the journal during the first and third periods. Terquem, Table 4. Percentage of the number of entries linked to four specific arithmetical thematic compared to the number of number theoretic entries in the N. A. M (the periodisation used here corresponds to the one advocated in [START_REF] Nabonnand | Un journal pour les mathématiques spéciales : les Nouvelles annales de mathématiques (1842-1927[END_REF]) Laisant and Bricard, among others, played here an important role by publishing articles or bibliographical reviews concerning these themes. Furthermore, they also seemed to encourage authors and readers to practice number theory by their multiple interventions in the journal.

Indeterminate analysis

Others

Period

IV -A variety of textual forms for the diffusion of "elementary" arithmetical content

Number-theoretical articles

From 1842 to 1927, 325 articles about number theory were published in the NAM Some of them contained developments directly linked to teaching programs. For example, Catalan and Thibault published articles about periodic fractions and Étienne Midy treated the resolution of indeterminate equations of the first degree by using the theory of residues, that is subjects included in the curricula. It is interesting to note that Midy insisted on the advantage of his method compared to the others and explicitly noted that it would be useful for students :

The next [method], based on the theory of residues, always will, we believe, at least, give an easier and quicker solution. It will also benefit to familiarize students with the principles whose application, while not yet widespread, can be very useful, and whose judicious use is very proper for exercising their sagacity. (Midy, 1845, p. 147) 11 .

Next to these memoirs dealing with teaching programs, several articles are published in order to introduce some arithmetical content as residues, congruences, or other results with higher arithmetic. For example, Prouhet wrote a memoir on the theory of residues and justified his choice in the following way :

That said, the subject of this memoir is the detailed and as much as possible complete study of the different systems of periods. Theorems that we demonstrate are not new; except for some developments, they are in the book of Legendre, but isolated and deduced from different theories. We thought it useful to bring them together and deduce one from the other in a uniform way. In addition, this work will also have the advantage of aiding young readers of this journal by providing them access to number theory, a difficult and still little cultivated part of mathematics, and on which now appears to rest the future of science (Prouhet, 1846, p. 178).

Elementary texts from Euler (1742Euler ( /1843) ) or Johann Peter Gustav Lejeune Dirichlet (1828) for example were also translated or summarized by Terquem. Some articles also echoed the contemporary research of number theory. For example, three notes by Terquem were included in the NAM between 1849 and 1850 about Fermat's Last Theorem, in connection with recent academic discussions (Verdier, 2009, p. 284-287). Some translations of German fundamental work was also included in the NAM : for example, a memoir by Jacobi on cyclotomy and quadratic forms (1856) and an article by Minkowski on geometry of numbers (1896). The fact that these higher arithmetical texts were inserted in NAM does not necessarily go against the editorial policy of the journal. Indeed, some of these texts fall within the "elementary", in the sense of Terquem, that is to say « everything is staged, well lit [...] and not requiring steps that are too high » (Kummer, 1860, p. 362;Verdier, 2009, p. 362-363) 12 .

Questions, exercises and answers

Some content was particularly designed for teachers and students in training. Many examination questions were reproduced in the journal, often along with a suggested correction. For example, in 1849, a question by Serret about continued fractions was inserted and treated in terms of congruences. Sometimes, exercices were proposed by the author, like Prouhet who concluded his memoir [START_REF] Prouhet | Mémoire sur la théorie des résidus dans les progressions géométriques[END_REF] on residues with two questions previously mentioned by Euler. As indicated before, the questions and answers could be linked to teaching programs and students represent a significant part of the problem solvers. Questions could also be linked to previously published articles. For example, the high school teacher Georges Fontené wrote an article on algebraic numbers in 1903, and one of his questions published in 1910 concerns the same theme. Some questions were also conjectures, as the one of Catalan (two consecutive integers, except 8 and 9, cannot be exact power. This conjecture is also published by Catalan in Crelle's Journal two years later.). More generally, mathematical questions circulated among several media. For example, several arithmetical questions published in the NAM were taken from books or periodicals such as the Educational Times or Sphinx-OEdipe, a journal published at the beginning of the twentieth century in Nancy by André Girardin, whose main subject was number theory.

Bibliography

The bibliographical section of the NAM informed readers of recent publications and included many reviews of textbooks. In the reviews, authors often focussed on the pedagogical qualities and defects of the treatises. Concerning number theory, we find several comments on the necessity of its inclusion in the elementary books. Thus, Terquem was laudatory about Joseph Bertrand's Traité d'arithmétique because "The arithmology finally enters the fundamentals. This is progress" (Terquem, 1849, p. 315) 13 ; in contrast, he wrote very critical reviews of the works of André Guilmin and P.-L. Cirodde because of their lack of number-theoretic content.

Between 1870 and 1890, we find in the NAM announcements of numerous articles in number theory -not necessarily elementary -published in foreign journals as Clebsch's Annalen, Bulletino di Bibliografia e di storia delle scienze matematiche et fisichen, Proceedings of the London Mathematical Society or American Journal of Mathematics. From the 1890', several reviews about number theory texts are also published. Thus, in 1895, we find the publication announcement of the fourth volume of the Récréations mathématiques of Lucas and for the Introduction à l'étude de la théorie des nombres et de l'algèbre supérieure by Emile Borel and Jules Drach, written from the lectures given by Jules Tannery at the École normale supérieure.

V -A desire to "spread" number theory

As was already mentioned on several occasions, through their multiple interventions in the NAM, several actors showed their desire to spread number theory in this journal. More generally, they demonstrated their desire to see this mathematical field gain a more important role in teaching and academic research in France.

Thus, when he was editor, Terquem regularly added notes at the end of the articles in order to justify his choices in the matter of publication. We can find several comments showing his will to value number theory. There are also some critical reviews on arithmetical treatises, mostly by Terquem again, that highlight the fact that the use of number-theoretical objects or results would greatly simplify the exposition of the subject. He also used his journal in order to comment on teaching programs :

Euler believes that number theory particularly is more able even than the geometry to give the rectitude of judgment and intensity to meditative faculty. If we introduced the main proposals of this theory in classical education, examiners would acquire an excellent criterion for classifying intelligences. This means is infinitely preferable to one that is in use, and that is difficult to make commonplace, accumulating puritan minutiae, more adapted to constrain minds than to make them free. Let us admit into our collèges calculus to facilitate, shorten, and extend studies, and number theory to increase strength. (Terquem 1846, p. 78) 14 .

Several volumes of the journal also contain reviews on recent number theory books, always underlining their importance and the fact that they are really good introduction for a mathematical domain that is fundamental yet absent in school curricula. Several authors, and especially Terquem, Laisant and Bricard, highlighted an important lacuna in French mathematical publication landscape: good introductions in modern number theory. That is why they advertised as valuable treatises in number theory -especially the one that were published in French -which according to them were relevant for the NAM's readership. Thus, Bricard praised two books published by Eugène Cahen, in 1900 and 1913. The Éléments de la théorie des nombres filled "in the French mathematical literature of our time, a regrettable gap in two points of view" (Bricard, 1900, p. 476) since the other French treatise devoted to number theory -the Théorie des nombres by Legendre -« has grown old in many ways and no longer meets current requirements ». For Bricard, Cahen's book was useful for two kinds of readers :

The book of Mr. Cahen perfectly fulfills this double program: on one hand, to expose parts of arithmetic that are essential for the full understanding of other theories; on the other, to be accessible to the most unprepared readers, not using any notion previously acquired. [...] The writing is very clear, the results are clearly explained, as and when they are acquired. Finally, there are many numerical examples for the reader to appreciate the practical value of the newly-exposed methods, which are all the while based on abstract considerations (Bricard, 1900, p. 477-478) 15 .

Here Bricard explicitly listed the values that have to be fulfilled by a good introductory book. Later, he continued to advertise books that he deemed were relevant for readers who needed to learn modern algebra and number theory. In his very brief presentation of the Lehrbuch der Algebra by Heinrich Weber, Bricard highlighted the quality of this shortened version of Weber's book: "The condensation of matter is worthy of remark " (Bricard, 1913a), a quality that allows readers to dive more easily into "modern Algebra ", notably through ideal theory. Bricard returned regularly to the need for quality French books on algebraic number theory and ideal theory (1913b).

The editors also used their journal to appeal the readers who wished to do original work in number theory :

If among the younger generation of French scholars, which has a future in front of it, there is someone to try to continue the tradition so sadly interrupted, it will contribute to the scientific glory of our country, and make in the same way the most fitting tribute to the memory of a geometer whose work was unappreciated in his lifetime to its real value, but that his [Lucas] Théorie des nombres ranks him among the masters of science (Laisant, 1892, p. 41) 16 .

VI -Conclusion : Various means for the NAM readership to access to Number theory

If a journal such as the NAM is not a teaching place of the same nature as a school, it is possible to distinguish, however, through an analysis of its contents, several forms of teaching practice.

First, this study has identified within the N.A.M. a large proportion of content concerning teaching curricula: some of this content contained results included in programs, others used number theory -as congruences -in order to simplify or to unify results about periodical fractions for example. A significant number of texts related to higher arithmetic are also published in this journal : original articles whose purpose is to introduce number-theoretical objects, such as residues, complex integers, quadratic forms, results, such as reciprocity laws, and translations, mostly from German articles, of fundamental arithmetical texts. In the absence of any French recent textbook on number theory, even if it is difficult to measure the effect on the audience, the NAM constitues one periodical resource with elementary content -in Terquem's sense -in number theory. The various bibliographic entries gave readers who did not study specialized mathematical journals or academic publications access to contemporary number theory. It seems that several actors -especially editors such as Terquem or Bricard -had an important role through their various publications and their editorial activities, for example, through their choices to ask for translations of given articles. Their presence on the editorial board is also consistent with the rise of the number of items on higher arithmetic for example.

Several authors, especially the editors, use the NAM in order to explicitly discuss the importance of number theory. At various occasions, number-theoretical topics -such as the geometry of numbers, or algebraic numbers -are valued by authors in articles or reviews. The importance of the integration of number theory into education is also regularly highlighted and readers are encouraged to study number theory in order to participate in the production of original research.

The fact that we can find comparisons with the situation in Germany is also particularly significant during the period 1870-1914. We can conjecture that this kind of discourse could have been relevant to promoting number theory to a readership who thought that it was fundamental that French science should progress to be able to compete at the international level, especially with Germany.

Finally, a mathematical periodical such as the NAM can be defined as a significant media to investigate attempts to introduce a mathematical field that was not well-represented in teaching programs. It provided elementary introductions in order to spread number-theoretical fundamentals, it gave some hints about current number theory, it encouraged the readers to practice number theory through submitting questions and answers, and it valued the importance of the domain for the training of human spirit. It is also seen as an efficient media to train young skilled arithmeticians, "among the younger generation of French scholars".

Table 1 .

 1 Number and percentage of the articles, questions, answers related to number theory (N. T.) respectively compared to the whole number of articles, questions and answers published in the N. A. M.

	Period	Articles in N. T.	Questions in N. T.	Answers in N. T.
	1842-1850	68 (8,5 %)	7 (11,1 %)	4 (1,4 %)
	1851-1860	55 (5,3 %)	27 (28,1 %)	19 (3,9 %)
	1861-1870	26 (4,9 %)	36 (7,4 %)	12 (1,9 %)
	1871-1880	72 (11,3 %)	52 (16,8 %)	54 (14,1 %)
	1881-1890	42 (6,6 %)	44 (19,3 %)	33 (22,6 %)
	1891-1900	16 (2,9 %)	16 (7,3 %)	8 (2,9 %)
	1901-1910	17 (3,6 %)	9 (3,7 %)	10 (3,4 %)
	1911-1920	27 (6,9 %)	7 (9,6 %)	17 (5,9 %)
	1921-1927	2 (0,9 %)	1 (2,2 %)	0

Table 2 .

 2 Repartition of the authors of the N. A. M. according to their professional status (the percentages do not take into account the 56 anonymous authors).

		Teachers	Teachers	Teachers	Students Military	Engineers	Religious Others	Anonymous
		(collèges,	(X, gvt	(Univ.)
		lycées)	schools)
	Number of	62	6	34	35	15	9	7	6	56
	authors
	Percentage 34,5 %	3,5 %	19 %	19,5 %	8,5 %	5 %	4 %	3 %

Indeterminate analysis, decomposition in forms Residues and congruences Continued fractions & periodic fractions

					Higher
					arithmetic
	1842-1862	30,3 %	9,1 %	11,1 %	3,5 %
	1863-1895	46,4 %	3,3 %	3,3 %	0,3 %
	1896-1927	24,2 %	8,9 %	1,6 %

« solutions claires, à la portée, et à la couleur des élèves ». This quote is issued from a letter from Terquem to Catalan dated August 31, 1849, and reproduced in(Verdier, 2009, p. 252). All the translations are mine.

«[Lucas] était en correspondance avec les plus illustres représentants de cette science [la théorie des nombres], si française par ses origines, et malheureusement si délaissée en France de nos jours. »

On this point, I refer for example to the correspondence between Legendre and Carl Gustav Jocab Jacobi. Thus, Legendre wrote to Jacobi February 9, 1828 : " but I prefer to give you advice not to give too much time to research of this nature [number theory]. It is very difficult and often leads to no result »(Legendre & Jacobi, 1875, p. 226).

« De toutes ces réflexions, et d'une foule d'autres que je pourrais y ajouter, je conclus donc que les principes de l'algèbre et de la théorie des nombres devraient être unis ensemble dans nos ouvrages élémentaires, comme ils sont inséparables par la nature même de ces deux sciences. »

« Cela posé, l'objet de ce mémoire est l'étude détaillée et complète autant que possible des différentes systèmes de périodes. Les théorèmes que nous démontrerons ne sont pas nouveaux ; à quelques développements près, ils se trouvent dans l'ouvrage de Legendre, mais séparés et déduits de théories différentes. Nous avons cru utile de les réunir et de les déduire les uns des autres d'une manière uniforme. Ce travail aura en outre l'avantage de faciliter aux jeunes lecteurs de ce journal, l'accès de la théorie des nombres, partie difficile et encore peu cultivée des mathématiques, et sur laquelle pourrait aujourd'hui reposer l'avenir de la science. »

« tout ce qui est bien étagé, bien éclairé, à ce qui n'exige point des pas trop élevés ».

"L'arithmologie pénètre enfin dans les elements. C'est un progress." « Arithmology » is a word meaning number theory used by Terquem, according to Ampère,

« Euler croit que la théorie des nombres en particulier est plus propre encore que la géométrie à donner de la rectitude au jugement et de l'intensité à la faculté méditative. Si l'on introduisait les principales propositions de cette théorie dans l'enseignement classique, les examinateurs acquerraient un excellent criterium pour classer les intelligences. Ce moyen est infiniment préférable à celui qui est en usage, et qui consiste à rendre difficile des lieux communs, à accumuler des minuties puritaines, plus propres à cambrer les esprits qu'à les rendre droit. Admettons dans nos collèges le calcul différentiel pour faciliter, abréger, étendre les études, et la théorie des nombres pour en augmenter la force. »

Le livre de M. Cahen remplit parfaitement ce double programme : d'une part, exposer les parties de l'Arithmétique qui sont essentielles pour l'intelligence complète d'autres théories ; de l'autre, être accessible aux lecteurs les plus dénués de préparation, en ne faisant appel à aucune notion antérieurement acquise.[….] La rédaction en est fort claire, les résultats sont mis nettement en évidence, au fur et à mesure qu'ils sont acquis. Enfin, de nombreux exemples numériques permettent au lecteur de se rendre compte de la valeur pratique des méthodes exposées, tout en le reposant des considérations abstraites. »

Si parmi la jeune génération de savants français, qui a l'avenir devant elle, il s'en trouve quelqu'un pour essayer de reprendre la tradition si tristement interrompue, il contribuera à la gloire scientifique de notre pays, et rendra du même coup le plus juste hommage à la mémoire d'un géomètre dont les travaux n'ont pas été appréciés de son vivant à leur véritable valeur, mais que sa Théorie des nombres classe parmi les maîtres de la science. »

Acknowledgment. This paper was presented under the general topic "Journaux et revues destinés aux enseignants et/ou consacrés à l'enseignement des mathématiques" proposed by Livia Maria Giacardi and Erika Luciano during the Fourth International Conference on the History of Mathematics Education and I want to thank them. I also warmly thank Sloan Despeaux for polishing the English of the present paper.