674 



NA TURE 



[May 2"], 1922 



Chemical Disinfection and Sterilisation. 



Chemical Disinfection and Sterilisation. By Dr. Samuel 

 Rideal and Dr. Eric K. Rideal. Pp. vii + 313. 

 (London: Edward Arnold and Co., 192 1.) 21^. net. 



IN the year 1909 the third and last edition of " Dis- 

 infection and the Preservation of Food " was 

 issued. It was a well-known and valuable work 

 written by Dr. S. Rideal, and the many who consulted 

 it will be struck, after perusing the volume under 

 review, with the similarity between the two publica- 

 tions. The new title " Chemical Disinfection and 

 Sterilisation " is a little misleading — for the methods 

 of disinfection described are not always chemical, and 

 the authors have much to say upon the subject of 

 antiseptics, which is neither " disinfection " nor 

 " sterilisation." 



There is no one in this country better qualified to 

 treat of the general subject of disinfection than Dr. 

 S. Rideal, so those who consult this book for informa- 

 tion on the science and art of disinfection may do so 

 with confidence. But often there will be felt some 

 regret that the information is not more detailed, 

 although the following extract from the preface dis- 

 arms criticism under this head. " Some apology is 

 needed for the method of presentation. Although 

 some of the problems which are briefly discussed are 

 already dealt with in extenso in a wide and varied 

 literature, others, equally important in their respective 

 fields, are scarcely mentioned in current text-books, 

 and it was felt that the inclusion of even a brief sum- 

 mary between the covers of one volume would appeal 

 to those whose interests cover this wide field, but who 

 have neither access to, nor leisure to study, the very 

 scattered literature on the subject." A valuable 

 feature of the work is the bibliographical information 

 at the end of each chapter, supplemented by many 

 useful footnotes. 



Chapter i is introductory and contains some interest- 

 ing historical references. Here the statement that 

 " cats and dogs have been shown to carry Diphtheria " 

 is open to challenge. Chapter 2 deals with the dis- 

 infection of air ; the reference here to the employment 

 of formic aldehyde vapour is particularly good. In 

 chapter 3 the sterilisation and preservation of food is 

 discussed. The inclusion here of the subject of metallic 

 contamination seems inappropriate ; and the poisonous 

 products of decomposition, the chemical preservatives 

 employed, and the pasteurisation of milk are far too 

 lightly touched upon. Chapter 4, upon the sterilisa- 

 tion of water, is perhaps the best and most helpful 

 chapter in the book and the authors are to be congratu- 

 lated upon an excellent and up-to-date statement. 

 Chapter 5 deals with public disinfection. The field is 

 NO. 2743, VOL. TO9] 



comprehensively surveyed, but the survey is not 

 detailed enough in many parts. For example, the 

 dozen lines devoted to the practical disinfection of 

 excreta are inadequate for the purpose of dealing with 

 this important and difficult subject. Chapter 6, dealing 

 with personal and internal disinfection, contains much 

 useful information. The reference to disinfectant 

 soaps is very full— fuller perhaps than their value, as 

 disinfectants, under the usual circumstances of their 

 employment, would seem to justify. 



Chapter 7, upon non-bacterial parasites (lice, scabies, 

 ringworm, fleas, etc.), is full of useful information. 

 The parasites of the lower animals are also dealt 

 with in this chapter. In chapter 8 the complex and 

 difficult subject of the pieservation of wood is appro- 

 priately treated, while chapters 9 to 13 deal with the 

 chemicals employed in disinfection. The relationship 

 between chemical and physical constitution and 

 germicidal activity is briefly but clearly treated. 

 Chapter 14 deals with methods of analysis and testing ; 

 and the Rideal-Walker evaluation test is of course 

 very fully considered, for it is a method which has 

 become widely adopted. 



One sympathises with the decision of the authors 

 to make no special reference to those disinfectants 

 which are proprietary articles, and yet the statement 

 seems incomplete when they are excluded, seeing that 

 some of the best liquid disinfecting agents !n practical 

 use come into that category. 



Full indices of subjects and authors close a book 

 which, despite certain defects (always of omission), 

 is a useful and authoritative statement upon the 

 subject with which it deals. 



Electrical Diagnosis. 



The Diagnosing of Troubles in Electrical Machines. By 

 Prof. M. Walker. (Longmans' Electrical Engineer- 

 ing Series.) Pp. xii + 450. (London: Longmans, 

 Green and Co., 1921.) 325. net. 



WHEN an electrical machine is not working 

 satisfactorily it is necessary for the engineer 

 to diagnose the trouble and, if possible, suggest a 

 remedy. The engineer in the works when testing the 

 finished machine has every scientific instrument at 

 his command. On the other hand the engineer 

 responsible for running machinery has only a few 

 voltmeters, ammeters and wattmeters available. Both 

 engineers, however, will probably find what they require 

 in the book under notice. It would be impossible 

 within the limits of a single book to deal with every 

 case that might arise, but there are several general 

 methods of procedure given by the author which if 



