FOODS HUMAN NUTRITION. 167 



cent, rospoctively. \vhil(> sLfi per cent of tin' eiierj^y of Ihe ralion is said lo l)c 

 availMl)lo. 



Vegetable cookery and meat substitutes, Sarah T. Koukk ( riiUiidclphia, 

 I'M'.), pp. 32S). — A collection of recipos and menus. 



Reform in our diet, M. Hindhede, ti'ans. by G. Bargum {Eine Reform uiiserer 

 Hrniihruiig. Copenhugcn and Lcipulc, 1908, pp. 232, pi. 1, flgn. .'/). — lu this trans- 

 lation into German from the Swedish it is stated that original new material has 

 I)een incorporated in the uiain portion of the volume, and additional material has 

 liceii added which has accnnuilated since the worlc was first printed. On the 

 basis of the experience of himself, his family, and others, the author advocates 

 a low proteid diet which in his own case consists of potatoes, bread, grits, fruit, 

 and considerable fat, with small amounts of meat, eggs, etc. The bulk of the 

 volume is taken up with summaries and discussions of literature bearing upon 

 . the subject. General suggestions are also made regarding the importance of 

 air, exercise, and other similar hygienic measures. 



Intracellular enzyms, H. M. Vernon (London, li)OS, pp. XI +240). — The 

 autlior has iiroseuted in this volume a course of lectures given at the Physi- 

 ological Laboratory of the University of London on proteolytic endoenzyms, 

 fat and carbohydrate splitting endoenzyms, zymase and other glycolytic enzyms, 

 oxidizing enzyms, the constitution and mode of action of enzj'nis, reversible 

 enzyni action, and endoenzyms and protoplasm. Indexes are provided. Of the 

 importance of the intracellular enzyms, or endoenzyms, and their relation to 

 biological problems, the following statements are made : 



" These enzyms differ from the exo-enzyms, such as are found in many of the 

 secretions of living organisms, by reason of the fact that they are bound up in 

 the protoplasm of the cells, and, so long as these cells retain their vitality, can 

 only exert their activity intracellularly. On death of the cells, the protoplasm 

 disintegrates, and many of the constituent enzym groupings gradually split off 

 and pass into solution. It is inferred, though strict proof of the inference is 

 wanting, that any zymolysing powers possessed by such solutions were, in all 

 jirobability, i)ossessed by the protoplasm before disintegration. And as a living 

 tissue would scarcely elaborate and store up within itse]f enzyms which were 

 useless to it, it is supposed that any enzym which can be extracted from a 

 tissue after death — apart from such enzyms as may be secreted externally dur- 

 ing life — was of functional importance during the life of the tissue. A thorough 

 study of all the zymolysing powers possessed by the disintegration products of 

 various typical tissues, vegetable as well as animal, is therefore of paramount 

 importance, for the knowledge so attained may lead us far toward the ex- 

 planation of the properties of living matter. It is possible that it may show 

 us that many or most of the catabolic processes of living tissues, and perhaps 

 the anabolic processes as well, are due to nothing more than the ceaseless 

 activity of a vast variety of endoenzyms, bound up together in the biogens, and 

 exerting their powers as they are needed. . . . This hypothesis of cellular 

 metabolism is not at present by any means completely established on a sound 

 experimental basis, but it is at least a working hypothesis, and one which can 

 only stimulate research, not retard it. Hence, even if it ultimatelj' prove 

 ernmeous, it needs no further justification. It is from the point of view 

 of the probable validity of this hypothesis that the experimental data col- 

 lected together in these lectures are described." 



On the occurrence of a phytin-splitting enzym in animal tissues, E. V. 

 .McUoi.LirM and E. B. Hart {Joio: Biol. Clinn., .', (IDOK). A'o.' «. pp. y.n-'m)).— 

 From the results of their exiK-rinients tlie authors conclude that "the liver and 

 blood li:i\c the i)roperty of cleaving the salts of phytic acid with the production 

 of innrganic phosphoric acid. The wide distribution of inosit in the tissues 



