June 16, 1916] 



SCIENCE 



857 



to a sound knowledge of the fundamental ideas 

 involved. As leading towards this the author 

 said he has always advocated personal instruc- 

 tion in the use and adjustment of instruments, 

 as well as the useful practise which may be 

 obtained in a students' surveying camp, but 

 that before either of these is possible the stu- 

 dent must have mastered the bedrock prin- 

 ciples, and the author hopes that a careful 

 perusal of the pages of the volume may help 

 him to do this. 



The book is disappointing and is not recom- 

 mended to the student of engineering nor to 

 the practising engineer as a guide or manual. 

 It seems to be more suited to the old-fashioned 

 county surveyor, with his Jacob's staff and 

 Gunter's chain, for the county surveyor of to- 

 day, in the United States at least, is more in- 

 clined to use the steel tape and the transit than 

 those old instruments, which should be rele- 

 gated to the museum. 



The chapter on " Calculations of Distances 

 and Heights" opens with the statement that 

 " It is assumed that the reader has some knowl- 

 edge of plane trigonometry." In this country 

 there is probably no school teaching surveying 

 which does not require a rather thorough 

 course in plane trigonometry as a preliminary 

 to the course in surveying. 



Under the heading, " Levelling and Contour- 

 ing " this signiiicant statement is made : " The 

 staff-holder should be very careful to see that 

 the particular spot of ground upon which the 

 stafi rests is fairly flat, and if the ground is of 

 a soft or spongy nature the spot should be 

 pressed down with the foot." This is not 

 teaching correct principles, for there is scarcely 

 any leveling which should not require solid 

 supports for the rod, and the earth, even if 

 " pressed down hy the foot" can not be con- 

 sidered a satisfactory rod support. 



The short chapter on " Geodetic or Trigono- 

 metrical Surveying " is almost entirely his- 

 torical and gives the student nothing which 

 would guide him in actual work. Even the 

 historical part does not include the recent de- 

 velopments and methods. 



The chapter on " Geodetic Astronomy " is 

 particularly disappointing, for it deals with 



only those methods which might be used in ex- 

 plorations and in determining the variation of 

 the compass. 



It is very difficult to see where or how such 

 a book has any useful purpose, for there are so 

 many other books available which are far better 

 for both the student and the engineer. 



WejLiam Bowie 



Diabetes Mellitus. By ISTellis B. Foster, M.D. 



J. B. Lippineott and Company, 1915. 



This is a model monograph for the modern 

 practising physician. Clearly written and not 

 too technical in language, it is still thoroughly 

 scientific in the mode of presentation. The 

 rapid advance in the knowledge of the fimda- 

 mental biochemical processes which take place 

 within the living body has nowhere been more 

 pronounced than in studies concerning the 

 nature of diabetes, a disease in which the 

 oxidation of glucose, a substance which ordi- 

 narily furnishes two thirds of all the chem- 

 ical transformations of the organism, has been 

 impaired or totally abolished. Dr. Foster has 

 presented all the essential details concerning 

 the pathological chemistry of diabetes, and has 

 at the same time written from that three-fold 

 standpoint which controls the value of a mod- 

 ern medical book, personal research, personal 

 clinical experience, knowledge of the research 

 and clinical experience of the best authorities 

 of the modern world. In no other book on 

 diabetes has the value of American work been 

 so fully recognized, and the reviewer feels that 

 it is the best book upon the subject which has 

 been written. 



Graham Lusk 



SPECIAL ARTICLES 



PERMEABILITY AND VISCOSITY 



In a recent article^ Spaeth has suggested 

 that the permeability of the surface layer of 

 protoplasm is determined by its viscosity, 

 which in turn depends on its colloidal condi- 

 tion. Increased permeability may be pro- 

 duced by increased colloidal dispersion, which 

 decreases viscosity and permits substances to 

 diffuse more rapidly into the protoplasm. An 



1 Science, N. S., 43 : 502, 1916. 



