948 



SCIENCE 



[N. S. Vol. XXXVII. No. 964 



who wish to make themselves acquainted with 

 mathematical methods in a limited time. The 

 importance of mathematics for all branches 

 of natural science will certainly increase the 

 more our knowledge progresses and increases 

 in complexity, because it becomes more and 

 more difficult to draw conclusions by non- 

 mathematical reasoning. A book of such 

 character as the one described can certainly 

 therefore claim to be of great importance. 

 E. Beutner 



EOCKEFELLEE INSTITUTE 



Chloride of Lime in Sanitation. By Albert 



H. Hooker. First Edition. New York, 



John Wiley & Sons. 1913. 



One of the most striking developments in 

 the art of water purification during recent 

 years has been the rapid increase in the use 

 of chloride of lime as a disinfectant. It has 

 been found that astonishing results may be 

 obtained by the use of surprisingly small 

 quantities of this substance. In clear water, 

 such as that of the Great Lakes, the applica- 

 tion of eight to ten pounds of this chemical 

 to a million gallons of water is sufficient to 

 destroy practically all of the bacteria. Larger 

 amounts are required for waters which con- 

 tain organic matter, in some instances nearly 

 one hundred pounds per million gallons being 

 used. Bleaching powder is also being used to 

 some extent in the disinfection of sewage. 

 Here, also, it has an important field of useful- 

 ness. 



The rapidity .with which the use of this 

 substance has come into popular favor is in- 

 dicated by the publication of the present work 

 devoted exclusively to the use of chloride of 

 lime in sanitation, and consisting chiefly of 

 abstracts of articles published in various 

 scientific journals. Four hundred of these 

 articles are quoted and the essential points of 

 each briefly stated. The author deserves 

 credit for having brought these various papers 

 together. It would be a tedious matter for 

 any one interested in this topic to obtain so 

 much information by his own search. Look- 

 ing for omissions the reviewer finds that the 

 compilation has been unusually well made. 



The abstracts are prefaced with an interest- 

 ing discussion of the general subject by the 

 author, who gives first a history of the manii- 

 faeture of chloride of lime and then an 

 account of the method of its use in water 

 purification and for other purposes of general 

 disinfection. In this he is somewhat inclined 

 to minimize the advantages of the use of 

 liquid chlorine. He regards the action of 

 bleaching powder as one of oxidation and 

 does not believe that chlorine acts by itseK 

 as a disinfectant in any other way than by 

 liberating nascent oxygen. Some may be in- 

 clined to question this. One of the most val- 

 uable sections of the book is that which gives 

 directions for dissolving bleaching powder 

 for its ^ practical application. Comparatively 

 little is said in regard to the corrosion of 

 metals by the use of this chemical. 



The book is well indexed and will prove an 

 invaluable reference book to sanitary engineers. 

 George C. Whipple 



The Plant Alkaloids. By Thomas Anderson 

 Henry, Superintendent of Laboratories. 

 Scientific and Technical Department, Im- 

 perial Institute. Philadelphia, P. Blakis- 

 ton's Son & Co. 1913. 

 So long as there is a science of botany, phy- 

 tochemistry will constitute a perfectly justifi- 

 able phase of chemical thought and of chem- 

 ical investigation. Though for a time, after 

 Kekule's enunciation of structural chemistry, 

 phytochemistry was looked upon as being not 

 fully up to date as compared with organic syn- 

 thesis, it is again coming to its own. Since 

 Emil Fischer has pointed out that some of the 

 most interesting problems of organic chemis- 

 try are those that are intimately related to bio- 

 chemistry, phytochemistry has once more be- 

 come a respectable science even in the eyes of 

 the synthetic chemist. 



The present activity in this field is mani- 

 fested not only by innumerable special re- 

 searches, but by the rapid growth of book liter- 

 ature. Thus Czapek's " Biochemie der Pfladz- 

 en," Euler's " Grundlagen und Ergebnisse der 

 Pflanzenchemie," and Wehmer's " Pflanzen- 

 stoffe," which have appeared within a short 



