510 ON THE INTERDEPENDENCE OF SCIENCE 



animal after it had already received a poisonous dose of the toxin, it preserved 

 the life of the creature, provided that too long a time had not elapsed after the 

 poison was introduced. In other words, the antitoxin proved to be not only 

 preventive but curative. 



Similar results were afterwards obtained by Ehrlich, of Berlin, with some 

 poisons not of bacterial origin, but derived from the vegetable kingdom ; and 

 quite recently the independent labours of Calmette of Lille, and Eraser of Edin- 

 burgh, have shown that antidotes of wonderful efficacy against the venom of 

 serpents may be procured on the same principle. Calmette has obtained anti- 

 toxin so powerful that a quantity of it only a 200,000th part of the weight of an 

 animal will protect it perfectly against a dose of the secretion of the poison-glands 

 of the most venomous serpents known to exist, which without such protection 

 would have proved fatal in four hours. For curative purposes larger quantities of 

 the remedy are required, but cases have been already published by Calmette in 

 which death appears to have been averted in the human subject by this treatment. 



Behring's darling object was to discover means of curing tetanus and 

 diphtheria in man. In tetanus the conditions are not favourable ; because the 

 specific bacilli lurk in the depths of the wound, and only declare their presence 

 by symptoms caused by their toxin having been alread}^ in a greater or less 

 amount diffused through the system ; and in every case of this disease there must 

 be a fear that the antidote may be applied too late to be useful. But in diphtheria 

 the bacilli very early manifest their presence by the false membrane which they 

 cause upon the throat, so that the antitoxin has a fair chance ; and here we are 

 justified in saying that Behring's object has been attained. 



The problem, however, was by no means so simple as in the case of some mere 

 chemical poison. However effectual the antitoxin might be against the toxin, 

 if it left the bacilli intact, not only would repeated injections be required to 

 maintain the transient immunity to the poison perpetually secreted by the 

 microbes, but the bacilli might by their growth and extension cause obstruction 

 of the respiratory passages. 



Roux, however, whose name must always be mentioned with honour in 

 relation to this subject, effectually disposed of this difficulty. He showed by 

 experiments on animals that a diphtheritic false membrane, rapidly extending 

 and accompanied by surrounding inflammation, was brought to a stand by the use 

 of the antitoxin, and soon dropped off, leaving a healthy surface. Whatever be 

 the explanation, the fact was thus established that the antitoxic serum, while 

 it renders the toxin harmless, causes the microbe to languish and disappear. 



No theoretical objection could now be urged against the treatment ; and it 

 has during the last two years been extensively tested in practice in various parts 



