REVIEWS. 471 



and that only such diseases were capable of passing from the 

 adult invertebrate host to offspring through infected eggs. Doc- 

 tor Ricketts has shown that both of these processes can occur 

 in bacterial diseases. How important these new biological facts 

 may prove to be is indicated by Doctor Ricketts' subsequent 

 investigations of typhus fever. The similarity of typhus fever, 

 in some respects, to Rocky Mountain spotted fever led him to 

 undertake the study of the former disease in Mexico. It was 

 during this investigation that Doctor Ricketts fell a victim to 

 the disease and died at Mexico City of typhus fever on May 3, 

 1910. It is a source of satisfaction to know that the sacrifice 

 was not in vain. Before succumbing to the disease, he dis- 

 covered, as in Rocky Mountain spotted fever, a small bacillus 

 which could not be cultivated upon artificial media, which is 

 probably that etiologic agent in typhus fever, and which appears 

 to be transmitted from man to man by the bites of the body 

 louse, Pediculus vestimenti. 



E. L. W. 



Manual of Practical Physiology. Designed for the Physiological Laboratory 

 Course in the Curriculum of the American Association of Medical 

 Colleges. By John C. Hemmeter, M. D., Ph. D., LL. D. With 55 

 illustrations. Philadelphia, P. Blakiston's Son & Co., 1012 Walnut 

 Street. 1912. Pp. i-xxii + 1-223. Price $2.50. 



One is favorably impressed on first opening this book. The 

 paper, type, and illustrations are good. The preface, but for a 

 passage or two, might lead the reader to expect an improvement 

 over the older manuals. Disappointment, however, begins with 

 the first page of the book proper and increases as one reads 

 further. The directions lack in definiteness, are wordy, and con- 

 descending. They contain irrelevant facts and irrelevant discus- 

 sions, they dwell on nonessentials, new matter is introduced 

 inopportunely, and inaccuracies abound. One or two quotations 

 will give an impression of the inaccuracy of thought and of 

 expression that pervades the book. On page seven, after the 

 statement of the equation for the strength of the electric current, 

 we read: "A simple example (presumably of the "electric cur- 

 rent") is the flow of water through a nozzle of a syringe." And 

 after speaking further about the syringe we find this: "Now 

 if the nozzle of the syringe is longer (pressure same) less HjO 

 would flow, or if the hole in the nozzle is made smaller the 

 same would happen, because in both cases resistance is increased. 

 Applying this to the electrical circuit we learn that the longer 



114707 i 



