COMBATING PARASITIC BACTERIA. 191 



entirely new means of assisting the body to fight 

 its battles with bacterial diseases. As already 

 noticed, one of the primal forces in the recovery, 

 from some diseases, at least, is the development 

 in the body of a substance which acts as an anti- 

 dote to the bacterial poison. So long as this anti- 

 toxine is not present the poisons produced by the 

 disease will have their full effect to weaken the 

 body and prevent the revival of its resisting 

 powers to drive off the bacteria. Plainly, if it is 

 possible to obtain this antitoxine in quantity and 

 then inoculate it into the body when the toxic 

 poisons are present, we have a means for de- 

 cidedly assisting the body in its efforts to drive 

 off the parasites. Such an antidote to the bac- 

 terial poison would not, indeed, produce a cure, 

 but it would perhaps have the effect of annulling 

 the action of the poisons, and would thus give the 

 body a much greater chance to master the bac- 

 teria. It is upon this principle that is based the 

 use of antitoxines in diphtheria and tetanus. 



It will be clear that to obtain the antitoxine 

 we must depend upon some natural method for 

 its production. We do not know enough of the 

 chemical nature of the antitoxines to manufacture 

 them artificially. Of course we can not deny the 

 possibility of their artificial production, and cer- 

 tain very recent experiments indicate that per- 

 haps they may be made by the agency of elec- 

 tricity. At present, however, we must use natural 

 methods, and the one commonly adopted is sim- 

 ple. Some animal is selected whose blood is 

 harmless to man and that is subject to the dis- 

 ease to be treated. For diphtheria a horse is 

 chosen. This animal is inoculated with small 

 quantities of the diphtheria poison without the 

 '3 



