September 20, 1912] 



SCIENCE 



375 



chemical constitution of their constituent 

 amino acids is extensively discussed and the 

 methods by which each of these amino acids 

 has been synthesized is described. The dif- 

 ferentiation of the proteins by means of the 

 proportion of the various types of nitrogen 

 which they yield on hydrolysis is given in 

 detail, as weU as the recent methods for esti- 

 mating amino nitrogen and also the nitrogen 

 belonging to the different groups of amino 

 acids. 



The book contains the iirst practically com- 

 plete compilation yet published of analyses 

 thus far made of the products of hydrolysis 

 of all the various individual proteins, a fea- 

 ture which will be appreciated by those work- 

 ing in this field of protein chemistry. In 

 commenting on these analyses the author very 

 properly emphasizes the fact that the per- 

 centages reported are in almost all eases min- 

 imal, and that none of the analyses repre- 

 sents the true amino acid make-up of the 

 protein; a fact too often overlooked by those 

 who have previously attempted to compile 

 such analyses, which simply reveal gross dif- 

 ferences between proteins of different origin. 



Plimmer's monograph, like the others of 

 this series, contains a very full bibliography; 

 but, unfortunately, references in the text are 

 not made in such a way as to readily show 

 the papers which are authority for the state- 

 ments made. This defect is especially appar- 

 ent in connection with the tables of analyses 

 of the proteins. Those who wish to quickly 

 and pleasantly inform themselves of what is 

 known of the chemical constitution of the 

 proteins, and of the methods by which this 

 has been learned, will find this monograph 

 exceedingly satisfactory. As an experienced 

 teacher of physiological chemistry recently 

 wrote the reviewer, " It strikes me as a re- 

 markably useful book; and it has more hu- 

 man touches than most reviews of this type." 



Thomas B. Osborne 



Physiologisches Prdktihum fiir Mediziner. 

 By Mas Verworn. Second edition. Jena, 

 Gustav Fischer. 1912. Pp. xii + 262; 141 

 illustrations. 



It is a curious fact that Germany, the coun- 

 try in which the science of physiology has 

 undergone its greatest development, has been 

 backward in providing laboratory instruction 

 in that science. And now that it is being 

 provided it is to be regretted that it is on a 

 lower pedagogic and scientific plane than in 

 the English and especially the American uni- 

 versities. The book before us is a second edi- 

 tion from Bonn of a work, the first edition of 

 which was issued from Gottingen five years 

 ago. It is a combination of the chemical and 

 the physical, about one fourth of the text 

 being devoted to the former. There is an 

 average of one illustration for less than two 

 pages of text. Each main topic is introduced 

 by a brief, concise and usually excellent sum- 

 mary of its physiology, and this is followed by 

 an elaborate account of the procedures to be 

 pursued in performing a series of selected 

 experiments. Most of the experiments are 

 well known to university teachers of the sub- 

 ject; but some are new, and a perusal of the 

 book will prove suggestive. Many experi- 

 ments which are frequently performed by stu- 

 dents in American universities are wanting, 

 and the only mammals employed, besides man, 

 are the rabbit, the guinea-pig and the white 

 rat. But the most striking feature of the 

 book is the elaborateness of the directions for 

 laboratory work, something with which we in 

 America are not familiar. The student is 

 never left to determine a procedure for him- 

 self, but is told exactly how to do the thing 

 desired. He must, for example, hold his 

 scalpel thus and so, the verbal directions being 

 supplemented by a nearly life-sized picture of 

 a hand holding the instrument; and he must 

 make " not little, shallow, short, hurried cuts 

 with the point of the knife, but long, firm, 

 quiet, deep incisions with its blade." In order 

 to tell how to make a frog's muscle-nerve 

 preparation two pages of text are required and 

 two additional pages of life-sized illustrations. 

 Eight pages, including illustrations, are em- 

 ployed in describing the customary method of 

 measuring the blood pressure in a mammal 

 with the simple action of the vagus nerve on 



