January 9 1908] 



NA TURE 



219 



parison. Thus in this country we have no cases of 

 towns corresponding to the Great Lalje cities — 

 Chicago, Cleveland, BuiTalo, Detroit, Milwaukee and 

 Duluth — drawing their water supplies from the same 

 limited area into which their sewage is discharged. 

 The risk of pollution is so abundantly evident that it 

 is not surprising that Chicago has attempted to mini- 

 mise the evil by diverting her sewage outfall, at 

 considerable cost, into the Mississippi River. The 

 wonder is that the example has not been copied in 

 other cases. 



Another strikingly distinctive feature is the enor- 

 mous excess of supply per caput over that generally 

 provided in this country. London and Liverpool 

 are each content with less than forty gallons per head 

 dailv. whereas ten large' American cities severally 

 and individually exceed a demand of loo gallons per 

 head. New York takes 129 gallons; Boston, 151 

 gallons; Chicago, 190 gallons; and Pittsburg, 250 

 gallons. The discrepancy is tremendous. One feels 

 that Mr. Hagen has hardly put it sufficiently strongly 

 when he remarks that, " taking it right through, 

 probably one-half the water supplied to American 

 cities is wasted." 



Mr. Hagen, in his book, first describes the various 

 available sources of supply, viz. artificial reservoirs, 

 small and large lakes, rivers, wells, and springs. 

 He then discusses the chemical action of water on 

 iron pipes and the means of effecting and maintaining 

 the purification of stored water. There are chapters 

 on pressure and on metering ; the financial side of 

 the subject is also considered. Altogether, the book 

 is a most useful compendium of information relating 

 to .American methods of water supply. 



VETERINARY PHYSIOLOGY. 

 A Manual of Veterinary Physiology. By Colonel F. 

 Smith, C.B., C.M.G. Third edition, completely 

 revised and in parts re-written. Pp. xvi + 715. 

 (London : Bailliere, Tindall and Cox, 1907.) Price 

 15X. net. 



AN interval of twelve years has passed between 

 the issue of the last edition of this text-book 

 and the present, third, edition. So many and notable 

 have been the advances in physiology during that 

 time that the book has had to be practically re-written ; 

 only the chapters on the senses, locomotion, and the 

 foot stand nearly as they were. The chapter on the 

 nervous system has been read, and some new matter 

 added to it, by Prof. Sherrington, F.R.S., and other 

 sections have been amplified by the cooperation of 

 men who have special knowledge of the particular 

 subject dealt with. 



The book is not a text-book of human physiology 

 with a little veterinary material added, but is a 

 treatise which takes the horse as the type, and pre- 

 serves that type throughout. Other animals of in- 

 terest to the veterinary surgeon are not thereby ex- 

 cluded; the ox, sheep and pig, where differing essen- 

 tially in their physiology from the horse, are fully 

 considered. A special feature of the work is the in- 

 terest it arouses in the reader; the physiology is 

 applied to the practical requirements of the student 

 NO. 1993, VOL. 77I 



and practitioner, and the book is, in its way, partly a 

 clinical manual. An appendix to many of the chapters 

 takes up shortly the more common features of path- 

 ological interest liable to occur in the organ or organs 

 the physiology of which has just been considered. 

 The addition of a little pathology is, in the words of 

 the author, meant to entorce the lesson that pathology 

 is only physiology out of health. It certainly adds 

 greatly to the interest of the book, and serves to 

 emphasise the importance of a thorough understand- 

 ing of the normal. 



For many of the discoveries in the physiology of 

 the horse we are indebted to the researches of Colonel 

 Smith himself, and no one is in a better position to 

 unfold them. This he does in the simplest and 

 clearest language; many of his statements, indeed, 

 throw light on processes which go on in the human 

 body, or are at least extremely suggestive. The ob- 

 servations, founded on universal experience, that, in 

 order to get a horse fit for hard work, or cattle and 

 sheep ready for the butcher, the diets given must be 

 stronglv nitrogenous and limited only by the appetite, 

 are quite opposed to the recent theories so strongly 

 advocated by Chittenden. This is not the only instance 

 where theory and practice come into opposi- 

 tion ; the custom of watering a horse before feeding 

 it is physiologically correct, but, according to Ellen- 

 berger, a horse, in order to derive the fullest possible 

 nutriment from its oats, should be given hay first, 

 then water, and finally oats. This does not accord 

 with the English views of watering and feeding 

 horses, which, however, as Colonel Smith says, have 

 stood the test of prolonged practical experience. 



The chapter on digestion is particularly good; the 

 horse, ox, pig, and dog are separately considered. 

 Occasionally one meets with statements that require 

 further amplification ; that pilocarpine is antagonistic 

 to atropin and produces a profuse flow of saliva reads 

 as though pilocarpine overcomes the effects of atropin, 

 and that nicotine paralyses ganglion cells is not 

 quite exact. The text, however, bears evidence of 

 careful revision, and the book will prove a most valu- 

 able one to veterinary students and practitioners. 

 Recent discoveries have been generally incorporated. 

 Special mention may be made of the chapter on 

 generation and development, which are particularly 

 well treated. The work is one that can be read with 

 interest from beginning to end, and claims the atten- 

 tion of all interested in veterinary work. 



Percy T. Herring. 



OUR BOOK SHELF. 

 The Polarity of Matter. By Alex. Clark. Pp. vii4- 



134; illustrated. (London and Edinburgh: Gall 



and Inglis, n.d.) Price 3s. 6d. net. 

 This book claims to be a trustworthy text-book for 

 the student of phvsics, but we cannot recommend it 

 in this respect. Very few of the statements of fact 

 which it contains are' correctly made ; and the deduc- 

 tions from them are supported by little consistent 

 proof. .\t least, these are the conclusions to which 

 we have come after a genuine endeavour to under- 

 stand the meaning of the book. At the present time, 

 when there has been such a rush of new facts, there 

 is abundance of room for a book of a speculative 



