The early years of the Lycée and the Lycée des Arts. A chapter in the lives of A. L. Lavoisier and A. F. de Fourcroy

The first professors at the newly-established London University (later University College London) were appointed in 1827, but a chair in geology was not created there until 1841. In the intervening years, teaching in geology and palaeontology was included in other natural science courses. Early in 1831, John Phillips, keeper of the Yorkshire Museum at York, was prompted to give a formal course of geological lectures and subsequently he was informally offered the professorship, which he declined.     

Technique d'inclusion et d'ultramicrotomie,destinée à l'étude du développement des organelles dans une cellule isolée

Summary (1) Control of cell orientation and knowledge of the plane of sectioning are indispensable (but generally ignored) requirements for studies of the development of cellular constituents. (2) A simple technique that meets these requirements for the electron microscope is given. (3) As applied toParamecium, it is shown that the ciliary complexes of the new gullet develop outside of the old one, and that invagination begins at the anterior end of the gullet anlage.

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Travail effectué dans le cadre d'une recherche faite en collaboration avec les Instituts d'Histologie et de Biophysique, grâce à une subvention de «Fritz Hoffmann-La Roche-Stiftung zur Förderung wissenschaftlicher Arbeitsgemeinschaften in der Schweiz».     

La question des hétérochromosomes chez les Sauropsidés. I. Reptiles

Summary In contradiction to some Japanese authors (Oguma, Makino, Nakamura), we are unable to find any difference in the chromosome sets of the male and female ofLacerta vivipara (2N = 36). In a saurian, where the analysis is very easy (Chamaeleon bitaeniatus), there are, without the smallest doubt, 24 chromosomes in both sexes (20M + 4m). The evidence of a female heterogamety in turtles is by no means satisfying.     

L'introuvable révolution scientifique. Francesco Redi et la génération spontanée

The Italian naturalist F. Redi established in 1668 that insects are not produced by the way of equivocal generation, contrary to what was affirmed since the Antiquity. For that reason, many historians of sciences acknowledge his experiments, like those of Galileo, Boyle or Huygens, contributed to the scientific revolution that emerges in the seventeenth century in Western Europe. Based on the commentaries sparked off by the works of Redi, in his time and today, our contribution shows on the contrary that nothing at all in his approach reveals such an intention. Questioning without arrogance the knowledge and the authority of the Ancients, careful interrogation of the literariness of the Scriptures, adoption of an experimental reasoning still dependent on the scholastic argumentation, those are the main characteristics of his work. But those also could be the ones of Harvey, Borelli or Swammerdam's works. To defend the idea of a scientific revolution in the life sciences similar in its conditions and tempo to the one described in the history of the physical sciences would be a mistake, not to say an anachronism.     

La question des hétérochromosomes chez les Sauropsidés. Oiseaux

Summary The chromosomes of the fowl were studied with the aid ofMakino's andNishimura's water pretreatment squash technique, modified byMatthey, in embryonic spleen and gonads of both sexes. The number of chromosomes was found to be about 78; the numerical variations are to be ascribed to technical difficulties, caused by the extremely small size of the microchromosomes, rather than to an unchromosomelike behaviour of the latter, as was supposed byNewcomer andBrant. As to the exact number of chromosomes, we consider its determination beyond the possibilities of cytology. The 5^th largest pair of the male, represented by a single element in the female, could be identified as the sex chromosome pair, in accordance with the findings ofYamashina. The digamety might be of theZ-O orZ-W type.     

Sur L'origine du ‘Principe Général’ de Jean Le Rond D'Alembert

This article intends to propose new hypotheses concerning the origin of the ‘Principe général’ of mechanics of Jean Le Rond D'Alembert expressed in its Traité de dynamique in 1743. The examination of the statics of Pierre Varignon and its inheritance suggests that D'Alembert retains, through a case of oblique collision on a hard surface, a method of decomposition and equilibrium of forces which is close to its principle. On the other hand, this principle requires a definition of the equilibrium widely spread in the 17th and 18th centuries, D'Alembert seeming then more to innovate from an epistemological point of view that on a technical one. Finally, the determination of rules of collision based at the same time on decompositions of movements at the level of the centre of mass and on appeal to a principle of relativity constitutes a know-how at the beginning of the 18th century which can be moved closer to methods developed by D'Alembert. These three aspects try then to replace the science of D'Alembert in a context by insisting on the essential role of the collisions of body and on that of the notion of equilibrium concerning the birth of its principle.     

Structure moléculaire et activité tuberculostatique dans le groupe des dérivés de la thiourée

Summary A large number of N,N-diarylthioureas and N-aryl-N-pyridylthioureas have been tested forin vitro tuberculostatic activity, and several of them have been found highly active. A series of 1-acyl-4-arylthiosemicarbazides have likewise been investigated, and most of them found to be active at a concentration of 10^–4; this is considered the basic activity corresponding to the molecular grouping -CO-NH-NH-CS-NH-.     

L'endocrinologie des invertébrés

Sans résumé     

Vernalisation deLinum austriacum L. par ablation des rameaux latéraux

Summary According to these experiments, it appears thatLinum austriacum L. needs vernalisation to bloom. The treatment at low temperature (vernalisation) may be replaced in the course of the first year by a process of mutilation, that is to say, the ablation of all lateral shoots as soon as they appear. The notion of the concentration of tropho-hormonal reserves in the aerial portion of the plant has been considered as a partial explanation of the phenomenon.     

Premiers résultats d'analyse fonctionnelle électro-biochimique sur l'oreillette isolée étalée deScyllium canicula

Summary A new method is described for studying the auricular automatism using quickly reversible inhibitors and dissociators of electrical and mechanical process. By means of carbon dioxide, acetylcholine, adenosine-triphosphoric acid and clupeine-sulfate, it has been found that the valve muscle is more resistant than the auricular muscle.     

De l'action radio-protectrice exercée sur la muqueuse rectale par la cystéamine administrée par voie générale et par la cystamine administrée par voie intra-rectale

Summary The authors studied the lesions observed in the rectal and vaginal smears of the rat after a local irradiation of the rectum. They observed that an injection of cysteamine before the irradiation strongly diminishes the ratio of damaged rectal and vaginal cells. A local treatment with cysteamine in the rectum before and during the irradiation diminishes only the ratio of damaged rectal cells.     

La biologie des hématinoprotéides oxygénables

Summary The author reviews a series of biological aspects of the study of oxygenable hematinoproteids, particularly with respect to evolution and adaptation. After a statement of some fundamental concepts of comparative biochemistry and of possible evolutionary relations between oxidation catalysts and oxygen carriers, the natural distribution of hemoglobins is reviewed and their specific characters are enumerated.A review is made of the data relating to the shape of the oxygen-dissociation curves and to the affinity of hæmoglobin for oxygen. It appears, generally speaking, that hyperbolic or almost hyperbolic curves and high affinity for oxygen are characteristic of primitive or embryonic hæmoglobins.A study of the function of hæmoglobin in the respiratory cycle of several animal species shows the vital importance of the oxygen carrier as well as the adaptation of the shape and position of the dissociation curve to the character of the respiratory function in the animal considered.The function of hæmoglobin in invertebrates, as oxygen carrier as well as providing a store of oxygen, is emphasized by a review of experimental data.The function of oxygen in the transport of carbon dioxide is reviewed from the standpoint of comparative biochemistry, and the lack of our knowledge is deplored.The characteristics of chlorocruorin show it to be a chemical mutation of an Annelid hæmoglobin.Our lack of knowledge in the field of the comparative biochemistry of hæmoglobin and chlorocruorin metabolism is pointed out.

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Conférence principale, présentée à la Société suisse de biologie médicale lors de la 127^e Assemblée générale de la Société helvétique des sciences naturelles à Genève, le 31 août 1947.     

Essais d'élaboration des voies d'approche à la chimiothérapie du cancer. Action sur l'eau d'hydratation des tissus néoplasiques; action sur les protéines

Summary The recent successes in chemotherapy suggest that a solution of the same order should now be possible for cancer. The cause of cancer being still unknown, the therapeutic action aimed at is the creation in the organism of conditions unfavorable for cell multiplication. Certain of the factors essential for cell growth, such as the hydrocarbons, have already been studied in this light. The author has demonstrated the possibility of influencing the high degree of hydration of tumor tissue by the use of substances capable of effecting a homogeneous distribution of the dispersed substances in the aqueous phase. Furthermore, it was proposed to influence the protein repair accompanying cell multiplication by means of substances having an affinity for proteins. This was done to effect a condensation of protein elements before they reach the tumor, thus producing a return to the normal concentration of the free protein fraction, and, at the same time, a decrease in the turn-over of these elements through the tumor. Electrophoretic measurements made with theTiselius apparatus have made it possible to follow protein affinity and to suggest the synthesis of compounds containing quinone and imine groups which may prove valuable in future investigations along these lines.     

L'état actuel de la théorie des particules élémentaires et des quanta

Sans résumé     

Inhibition de la cancérogenèse spontanée chez les souris R III et AkR par des implants de tissus cancéreux modifiés

Summary (1) After a 24-h passage in a rabbit, fragments of spontaneous isologous mammary carcinoma were implanted under the skin of young R III females. This procedure was found to prevent the appearance of spontaneous mammary tumours in a high percentage of these animals. The subsequent appearance of carcinoma was to be observed in only 23% of treated animals as compared with 51% in controls.(2) After a 24-h passage in a rabbit, fragments of leukotic isologous tissue, implanted subcutaneously in young AkR females, reduced subsequent spontaneous leukomogenesis from 85 to 38%.     

Action de l'eau oxygénée sur un anaérobie strict

Summary A quantitative study on the action of H₂O₂ uponCl. saccharobutyricum shows that the primary action is produced upon a first substance X, very likely an enzyme, following a mechanism such as one equivalent of oxygen gives a reversible combination, and two equivalents an irreversible combination.     

L’émergence contrariée du chronographe imprimant dans les observatoires français (fin 19e – début 20e s.)

Les observatoires occidentaux se transforment en véritable usine scientifique à partir du milieu du 19^e siècle. L'astrométrie symbolise ce passage à une économie industrieuse des pratiques scientifiques. Le chronographe imprimant, qui permet de réduire les équations personnelles des observateurs, s'impose, d'abord aux Etats-Unis, puis en Angleterre, en instrument-emblème de cette transformation profonde. En France, les initiatives de l'astronome Liais restent prototypiques. Ce n'est qu'au début du 20^e siècle, par les voies détournées de l'observatoire d'Hendaye et de l'abbé Verschaffel, que le chronographe imprimant fait son retour et conquiert les espaces savants. La centralisation excessive de l'astronomie française, l'autoritarisme du directeur de l'Observatoire de Paris Urbain Le Verrier, et la faiblesse du marché des instruments expliquent pourquoi le chronographe imprimant n'a fait souche que très tardivement en France.