240 



SCIENCE 



[N. S. Vol. XLV. No. 1158 



SCIENTIFIC BOOKS 



Water Supply. By William P. Mason. 



Fourth Edition. New York, John Wiley 



and Sons, x + 528 pages, 6/9. $3.75 net. 



The fourth edition of Professor Mason's 

 well-known book on water supply testifies to 

 the high esteem in which this book is held by 

 the American engineering public. Published 

 originally in 1896 it has passed through sub- 

 sequent editions, each time being substantially 

 enlarged and improved. For the present edi- 

 tion a large amount of the text has been en- 

 tirely rewritten and suitable amount of new 

 material added. The tables have been brought 

 up to date and new photographs introduced. 

 Some of the most noticeable changes are the 

 following : 



The chapter on Drinking Water and Dis- 

 ease has been strengthened by the addition of 

 many pages devoted to typhoid fever. The 

 work of recent years is drawn upon to set 

 forth present-day conceptions in regard to 

 the existence of the typhoid bacillus ou.tside 

 its human host and in " carriers." The dis- 

 tribution of the disease and factors operating 

 in its transmission are also discussed. Con- 

 siderable material has been withdrawn from 

 this edition relative to the now discredited 

 theory of water-borne malaria. 



Newly developed methods of water purifica- 

 tion, particularly processes aiming at disin- 

 fection, come in for consideration, as do cer- 

 tain newly found factors influencing natviral 

 purification in streams and stored waters. 

 The use of chlorine ozone, ultra-violet light 

 and copper sulphate receive attention. There 

 is considerable discussion of various phases 

 of the pollution of drinking water supplies and 

 the care of watersheds. 



Revisions and additions appear frequently 

 throughout the chapters dealing with ground 

 water and with the corrosive action of water. 

 The appendices deal with entirely new sub- 

 jects and are brief. 



Professor Mason is always a pleasing writer 

 and has the art of abstracting the important 

 data from the writings of others and pre- 

 senting them in an attractive form. Although 

 this can not be called an exhaustive treatment 



of the subject it is one of the most interesting 

 and suggestive treatises on water supplies pub- 

 lished since the old book of the same title by 

 Professor William Eipley Nichols, of the 

 Massachusetts Institute of Technology. 



George C. Whipple 



HaEVAED UNiyERSITY 



Sarcophaga and Allies in North America. By 

 J. M. Aldrich. Published by the Entomo- 

 logical Society of America. Lafayette, Indi- 

 ana, 1916. 



In 1915 the Entomological Society of Amer- 

 ica, recognizing the difiiculty of adequately 

 publishing monographs on American insects, 

 established the Thomas Say Foundation for 

 this purpose. Subscriptions were solicited, 

 and the accumulating funds were set aside to 

 be used from time to time as suitable works 

 might be offered for publication. The plan is 

 not unlike that of the English Ray Society, 

 which has been publishing important zoolog- 

 ical works for .many years. Very appropri- 

 ately, the Foundation is named after Thomas 

 Say, the founder of American entomology. 

 The first monograph issued imder these au- 

 spices is now before us, and is a revision of 

 the Sarcophagid flies, commonly known as 

 flesh-flies, by Dr. J. M. Aldrich. These flies, 

 which are very abundant in America and Eu- 

 rope, and in some cases of considerable eco- 

 nomic importance, have long been the despair 

 of students. It was recognized that the spe- 

 cies were numerous, and in fact over a hun- 

 dred supposed species had been described, but 

 no one could satisfactorily identify them. 

 About twenty years ago L. Pandelle published 

 a work in France, in which he separated the 

 European species known to him by the charac- 

 ters of the sexual organs. This method proved 

 brilliantly successful, and after a time was 

 confirmed and adopted by the other European 

 workers. It is now applied to the American 

 flies, with the result of making the whole sub- 

 ject over, and replacing chaos by order. Dr. 

 Aldrich has been able to recognize 145 species 

 and varieties in the American fauna, and 

 figures the genitalia of 138. Every reasonable 

 effort has been made to identify the earlier 



