vi PREFA CE 



reaction is not a true antigen test, are but a few instances 

 of many which occasionally intrude to mislead the unwary 

 bacteriologist and to confuse those who rely on his findings. 

 So far as space allows, we have briefly indicated where, 

 why, and how, errors may be expected and avoided. 



Surgeons on military service, when first called on to deal 

 with the complicated wounds caused by the pointed-nose 

 bullet and contaminated with resistant faecal organisms 

 carried in from soil and clothing, found methods then current 

 for antisepsis quite inadequate. Discussion of the relative 

 values of antiseptics for surgical use continues, the ten- 

 dency at present being to use those dependent for action on 

 the oxidising properties of chlorine. Sir Almroth Wright 

 tackles the problem of cleansing wounds by the applica- 

 tion of very strong saline solution, which results in a con- 

 siderable exudation of serum. Though it has no gcrmicidal 

 action for the streptococci, this process is much used, in- 

 voking both praise and criticism. Magnesium sulphate 

 and glycerin are also used, and, it is said, kill the strepto- 

 cocci (A. E. Morison's process). 



Bacteriology promises to modify agricultural methods, 

 and in Chapter XX. we give resumes of what has been 

 accomplished in soil-sterilisation and nitrogen-fixation. 



While most bacteriologists have had some personal ex- 

 perience of bacterial mutability, to which we make fre- 

 quent reference, this remains largely of academic interest. 

 In practice, species tend to crop up fairly true to type, and 

 exceptional conditions are usually required to produce 

 important change in attributes. 



C. G. M. 

 W. P. 



LONDON, 



May, 1916. 



