364 Chapter XII 



has no action on the organism. The hyposulphite of soda, then, acts 

 as the antitoxin of the prussic acid, thanks to a chemical reaction of 

 substitution between bodies of simple composition. We have never 

 yet succeeded in reproducing this reaction in vitro, whilst in the 

 animal body it is effected with very great ease. Consequently, we are 

 quite justified in invoking special conditions in the body of the 

 living animal ; this, however, does not preclude the possibility of a 

 transformation of the toxic substance into an innocuous substance 

 through a chemical reaction. It is probable that analogous phe- 

 nomena may also be met with in the action of true antitoxins on 

 the microbial toxins or allied substances (venoms, vegetable toxal- 

 bumins). 



The case of the destruction of micro-organisms, which is now more 

 easily studied because it is possible to observe with the eye the fate 

 of these organisms in the animal, is a further source of valuable 

 information. The direct action of cytases on certain bacteria, such as 

 the cholera vibrio, can be just as easily demonstrated in vitro as can 

 the action of antiricin on ricin. If we proceeded to argue from this, 

 a perfectly accurate observation, that the living animal plays no part 

 in the destruction of the micro-organisms and that this destruction 

 takes place always in a fashion analogous to Pfeiffer's phenomenon 

 in vitro, we should undoubtedly arrive at an erroneous conclusion. 

 We know already, as has been indicated in previous chapters, that 

 the granular transformation of vibrios is only part of a whole 

 series of phenomena of destruction of micro-organisms, the great 

 majority of which phenomena require more or less active inter- 

 vention of the animal organism. In reality, matters usually go on in 

 a very complicated fashion, in which direct and indirect actions are 

 blended in varied proportions. In the examples described elsewhere, 

 we see, alongside the granular transformation, an agglutination into 

 [383] clumps and immobilisation, and an ingestion and intracellular de- 

 struction of micro-organisms. The final phase, no doubt, is always 

 a chemical or physico-chemical action, exerted against the micro- 

 organism, but how varied are the means used to bring about this 

 result ! We may surely be allowed to suppose that- analogous pheno- 

 mena may take place in the action of antitoxins on the toxins. 



Just as, in the analysis of the influence of serums on the micro- 

 organisms, it was found useful to study the action of certain fluids 

 less complicated than the anti-infective specific serums, so we may 

 utilise information furnished by the antitoxic action of fluids other 



