104 ACTION OF ANTISEPTICS 



enzymes, and one which is now often used for the purpose on this 

 account is toluol. Another substance said to be almost without 

 action on enzymes, but most toxic for cells, is hydrocyanic acid ; 

 it stops, however, the property of acting upon hydrogen peroxide 

 which is common to nearly all enzymes. Such substances as 

 antiseptics and anaesthetics produce their effects by combination 

 with proteid or protoplasm ; and since all enzymes and cells must 

 be allied in consisting of colloids related in character to proteid, 

 it is evident that an ideal substance which will affect the cell and 

 not the enzyme is an impossibility. As a result, we have no hard- 

 and-fast criterion as to whether a given effect is produced by an 

 enzyme or a living cell, except where living cells can be ruled out 

 by microscopic examination. For, while active cells are thrown 

 out of activity by protoplasmic poisons much more readily than 

 enzymes, there exists, bridging over the interval, the sporing 

 form of the cell, which shows the same resistance to the chemical 

 reagents that we have already seen in the case of changes in 

 temperature. 



The only true test is that of being able to grow and produce 

 the cell in pure culture, and then obtain with it the previously 

 observed chemical or biological effect. Unfortunately, this in 

 many instances fails, notably in the case of many of the commonest 

 infectious diseases, and we are left unable to trace with certainty 

 the causation of the disease to any particular micro-organism. 



A good example of this is to be met with in the case of ordinary 

 vaccine. As is now well known, thanks to the labours of Copeman 

 and of Green, this can be kept in contact with glycerine, or better, 

 with chloroform water, until all extraneous, organisms have 

 perished, and nothing can be grown from the preparation in culture 

 media ; yet the virus is still present in almost unabated power, 

 as is shown by obtaining the typical effect on vaccination. 



The virus may here either be a very resistant spore, which 

 remains alive after all the other organisms have been destroyed 

 by the chloroform, which cannot be cultivated upon ordinary 

 nutrient media, and only commences to develop in the serum of 

 the living body after vaccination ; or it may be that the virus 

 of vaccine, as suggested by the writer, 1 is an enzyme with the 



1 " A Chemical Theory as to the Propagation and Development of Certain 

 Infectious Diseases," The Journal of State Medicine, April 1904. 



