ACTION OF VESICANTS 93 



for long the systemic effects of mustard gas and of 

 lewisite tended to escape study. Attention was particu- 

 larly directed towards the systemic effects by Cameron, 

 who pointed out that in the long run the systemic effect 

 might be much more important than the skin lesion. 

 Subsequently many studies have been made of the basis 

 of the systemic effects. Peters inclines towards the view 

 that the main effect is produced by the inhibition of 

 pyruvic oxidase, whereas DixoN and Needham incline 

 to the view that various phosphokinases may be con- 

 cerned, amongst which may be part of the pyruvic oxidase 

 system. Various cytological approaches have also been 

 made to this problem. Robson, Auerbach and Roller 

 have indicated that the action of mustard gas may be 

 primarily on the nucleus of a cell. They have shown that 

 mustard gas is mutagenic and prevents mitosis. American 

 workers have emphasised the action of mustard gas on 

 cell membranes — red blood cells, Nitella, leucocytes, and 

 lung cells have been studied and all appear to have their 

 membrane properties significantly changed by amounts 

 of mustard gas which would not exercise any profound 

 effect upon intracellular enzymes. It has also been pointed 

 out that there are many points of resemblance between 

 mustard gas poisoning and radiation sickness. 



From this survey of studies on vesicants it must be 

 plain that whilst studies on enzyme systems are often 

 very suggestive, yet it is often extremely difficult to obtain 

 incontrovertible proof that a particular inhibition of one 



