280

Revue des livres.

Sergs VoronoJJ, Lcs sourccs de la vic. Paris, Basquellrs. Ed. 1!)33. p. 184. Ce livre du celhbrc auteur est adapt6 au public inteltectuel ct nc s’adresse

pas specialemcnt anx mkdecins. I1 n’en ent pas moins h i t sous une forme si spirituelle e t ouvre des vues si vastes et si interessantes sur l’origine de la vitalit6 et sur sa dependance des glandes gbnitales yu’il mbrite d’btre lu par tout le monde, y compris les nibdccins.

I . Holtrcyren.

J. Sim Wallace, The physiology of oral hygiene and recent research. London, Baillibre, Tindall & Cox. 228 p.

The 12 chapters which make up this book are independent communications whic,h the author has been called upon to read on various occasions. This accounts for lack of co-ordination and some repetition as he himself points out in the pre- face. Nevcrtheless the book is excellent and very interesting. In some parts the author is more agitator than scrupulously weighing scientist. His sarcasms against the medical profession are perhaps somewhat exaggerated. But many of us are dcserving of such a criticism. The capital point in the book is the discussion of the cause and prevention of caries. He defends with great skill and good reason his own views. They can be summarized as follows: there is no hereditary predisposi- tion for caries, neither is there any immunity or non-immunity. Vitamin deficiency, bypoplasia, microscopical structure of tho teeth have nothing to do with the caries. Thc caries depends entirely on hacterio-chemical processes in the mouth. The immediate cause of the decalcification of enamel, which starts the caries is the acid, formed by microorganisms fermciiting carbohydratcs. These acid forming micro-organisms are the active cause of caries. The condition necessary for their production of acid is the lodgment of fcrmentablc carbohydrates in the reten- tion arcas of the teeth, and without this condition caries never arises. Caries de- pends then on carbohydrate stasis in the mouth. Does such stasis exist, caries always follows indepentlcnt of vitamins in the food or other internal conditions. The caries can easily be prcvcnted if we avoid such carbonhydrates as are the best able to cause rapid acid fermentation and which havc a spccial tendency to lodge about the teeth, that is in the first place concentrated sugar in tho form of sweets, jam and marmalade. For t h i s rcami every meal should he arranged in such a way tlic the food, last caten, is cleansing in character. For this purpose uncooked fruit is generally the most convenient and agreeable. The reason for the general freedom from caries among primitive races, as compared with us, is that their food is more of the fibrous type, which stimulates maNtication and is not of a par- ticularly fermentable nature, evcn when of vegetable origin. All medical men should read this book as we are all in urgent need for hetter knowledge of the important practical questions connected with oral hygiene.

I. Holmgren.