DISCOVERY 



223 



Books Received 



(Mention in this column does not preclude a review.) 

 MISCELLANEOUS 



Sidney Ball. Memories and Impressions of " An Ideal 

 Don." Arranged by Oona Howard Ball. (Ox- 

 ford ; Basil Blackwell, los. 6d.) 



Statistical Bibliography in Relation to the Growth of Modern 

 Civilisation. By E. Wyndham Hulme, B.A. (But- 

 ler & Tanner, Grafton & Co., 6s.) 



Ben Jonson's Conversations with William Drianmond oj 

 Hawthornden. Edited by R. F. P.attersox, M.A., 

 D.Litt. (Blackie & Son, Ltd., 75. (,d.) 



Studies in Religion, Folk-lore, and Custom in British 

 North Borneo and the Malay Peninsula. By I\oR 

 H. N. Evans, M.A. (Cambridge University Press, 

 2.0s.) 



The Growth of the City State : Lectures on Greek and Roman 

 History, First Series. By Professor W. R. H.alli- 

 DAV, B.A., B.Litt. (University Press of Liverpool, 

 Ltd., and Hodder & Stoughton, Ltd., js. 6d.) 



The Children of the Stm. A Study in the Early History 

 of Civilisation. By W. J. Perry, M..A.. (Methuen 

 & Co., Ltd., 185.) 



The Birth of Psyche. By L. Charles-B.^udouix. Trans- 

 lated by Fred Rothwell. (George Routledge & 

 Sons, Ltd., 55.) 



Our Phantastic Emotions. By T. Kexrick Sl.\de, 

 B.Sc. (Kegan Paul, 6^-. (>'d.) 



SCIENXE 



Special Steels. By Thos. H. Burxham, B.Sc. (Sir 

 Isaac Pitman & Sons, Ltd., 5s.) 



This book is a double number of one of Pitman's Tech- 

 nical Primers, the excellence and cheapness of which 

 have been mentioned more than once in these columns. 

 All steels other than ordinary' carbon steel are described 

 with reference to their constitution, their manufacture, 

 and heat or other treatment. The book should prove a 

 useful compilation both for the student and the practical 

 man. 



The Elementary Principles of Lighting and Photometry. 

 By J. W. T. Walsh, M.A., M.Sc. (Methuen & Co.. 

 Ltd., los. (>d.) 



A good account of the whole subject by a member of 

 the staff of the National Physical Laboratory. It is the 

 first connected attempt, we think, to bring the pre-war 

 books on the subject up to date, and gives an informed and 

 interesting account both of present-day theories and cur- 

 rent practical work. 



Essentials of Modern Physics. By Charles E. Dull. 

 (G. G. Harrap & Co., Ltd., 55.) 



.\n easily read, accurate, American book, semi-popular 

 in tone and well illustrated ; intended to be read more 

 for general information than to defeat examiners, and 

 including detailed accounts of ' wireless " and of the 

 mechanism of the automobile. 



Dates and Date Cultivation of the 'Iraq. Part III. The 



Varieties of Date Pahns of the Shaft Al 'Arab. By 



^^ H. W. Dowsox, B.A. (Hefier & Sons, Ltd., 105.) 

 Practical Wireless Sets for All. Home Construction Made 



Easy. By P. W. Harris. (The ^^'ireIess Press, 



Ltd., IS. 6d.) 

 The Constitution of Matter. By Max Borx. Translated 



by E. W. Bl.\ir and T. S. Wheeler. (Methuen & 



Co., Ltd., 65.) 

 Heat and Energy. Bv D. R. Pve. (Clarendon Press, 



Oxford, 5s.) 

 Practical Bacteriology for Chemical Students. By David 



Ellis. (Longmans, Green & Co., 4s. 6d.) 

 Practical Plant Ecology. A Guide for Beginners in Field 



Study of Plant Communities. By G. A. Taxsley, 



M.A., F.R.S. (George Allen & Unwin, Ltd., ys. 6d.) 

 Ductless and Other Glands. By Professor Fred. E. 



Wyxxe, B.A., M.B., D.P.H., etc. (George Allen & 



Unwin, Ltd., 4s. 6d.) 



Correspondence 



THE BACTERIA OF THE SOIL 



To the Editor of Discovery 

 Sir, 



Concerning the above article by Mr. P. H. Gray, 

 of Rothamsted, in your interesting publication of June 

 this year, I wish to know if the following line of thought 

 has been investigated. 



I believe it is accepted that nitrification and denitrifica- 

 tion are products of the ferments of organic matter, the 

 proportion of one species of organism to its opposite in 

 a given sample of humous soil depending upon aeration 

 or oxygen supply and mineral en\'ironment. These two 

 species of bacteria are saproph\i:es in anabohsm and 

 catabolism, but am I right in assuming that the denitrify- 

 ing organisms become septic parasites during fermentation 

 of purely organic substances — hence tetanus, typhoid, 

 tubercle bacillus, etc. ? Can you tell me if any experiments 

 have proved productive of results in tracing the origin 

 of such parasites ? 



Further, as the most important antiseptics, such as 

 alcohol, with its Bacillus aceticus, phenol, as mentioned 

 in your paper, and the others, nicotine, etc., presumablj^ 

 have their ferments, sterilisation is therefore, as Pasteur 

 thought, a matter of thermal consideration only. 



Thanking \'ou in anticipation of considering an amateur's 

 enquiry. 



Yours, etc., 

 30 FjVIRMile Avexie, C. G. Bishop. 



Streatham, S.W.16. 

 June 25, 1923. 



[The points raised by Mr. Bishop are of some importance, 

 since there is frequently misunderstanding on the question 

 of bacteria in general and those which cause disease. Of 

 the many thousands of species which have been described, 

 only a few dozen familiar forms of bacteria can withstand 

 the rigorous conditions inside the animal organism and 



