Jacques Guillerme : Oxygen and therapeutics. The advances of pneumatic chemistry at the end of the century and the emphasis on the preeminence of oxygen inevitably led to creative trends in therapy. Although effective in cases of asphyxia, the stimulating properties of 'vital air' were soon found to be incapable of curing chronic diseases. However, the prestige of its stimulating properties was such that it gave rise to indirect therapy, using oxygenized compounds which were generally ineffective and/or hazardous. Many rationalisations were found, based on Brownian 'Stimulism', and often also on the fact that they followed the pattern of formalisation of applied mathematics. The aim of this article is to retrace the various stages of a therapeutic error which came to an end when rational empiricism was restored, together with a denial of chemistry's ability to account for the mechanism of life.

François Azouvi : Irritability and animal magnetism : an unpublished letter by Servan. This unpublished letter, which dates probably from 1785 or 1786, comments on Tardy de Montravel's theses concerning magnetic somnambulism. In order to explain the facts presented by the magnetists, Servan proposes to use the theory of irritability, as revised by the Monpellier school. Servan — who had little confidence in 'systems' but wished to remain faithful to the facts — was seeking a middle way between credulity and scepticism.

Aram Vartanian : Maupertuis' brother and the «homme machine ». Maupertuis' younger brother, Moreau de Saint-Elier, who is now all but forgotten, was the author of a Traité de la communication des maladies et des passions (1738). This work, which consists mainly of a discussion of the breast-feeding of infants, is one of the earliest crypto-materialist texts to be published in the Enlightenment. Saint-Elier 's exposed an «histoire naturelle de l'homme » (the phrase, which forms the book's sub-title, was his own) as the theoretical basis of his position against breast-feeding. Of more special interest are the close textual and thematic parallels between Saint-Elier's psychophysiological anthropology and La Mettrie's L'Homme machine (1747). These parallels assume greater significance when it is realized that La Mettrie and Maupertuis' brother must have known each other in Saint-Malo, and exchanged views on scientific and philosophical topics, in the period from 1734 to 1742.

Paul Hoffmann : The theory of the soul in medical thought around 1778. The Nouveaux éléments de la science de l'homme, published in 1778 by Joseph Barthez, represent the problems facing anthropologists in the 18th Century, caught between mechanism and animism. Barthez sought a new objective scientific language, but continued to use the term "vital principle" to denote the specific nature of living beings and to mark his distance from materialistic physiology. His vital principle, which was simply a working concept, was difficult to reconcile with the soul ; the ensuing difficulties could only be solved by a vitalism which he attempted to avoid but which was the only possible refutation of mechanism. The probfems encountered by Barthez and the ambiguity of his theory of the soul are therefore exemplary.

Marie-José Baudinet : The body and the inanimate in still-life. It is now possible, in the light of recent studies, to analyse still-life painting in a new way. Faced with these tables and buffets, we must consider 18th-century life in the stillness of its digestions, but also death, present in the designation «nature morte ». The representation of food becomes a metaphor for the living body, fixed on a canvas, explicitly abstracted from life. The paintings of Jean Etienne Liotard (1702-1789) have been chosen for his exemplary use of food and skin, and because his Traité de la peinture expresses what is hidden in the painting : the pox. Thus still life is part of the history of the suffering, mortal and lustful body. It is not surprising that it should predominate on the eve of a bourgeois revolution which ushered in the industrial era.