454 THE LIFE OF PASTEUR 



surface; I shall tell the mother to purify herseK like a Hindoo 

 — else what would you say to me ! " 



A German of the name of Klebs discovered the bacillus of 

 diphtheria in 1883, by studying the characteristic membranes; 

 it was afterwards isolated by Loeffler, another German. 



Pure cultures of this bacillus, injected on the surface of the 

 excoriated fauces of rabbits, guinea-pigs, and pigeons, pro- 

 duce the diphtheritic membranes: Messrs. Roux and Yersin 

 demonstrated this fact and ascertained the method of its deadly 

 action. 



Dr. Koux, in a lecture to the London Royal Society, in 1889, 

 said: '* Microbes are chiefly dangerous on account of the toxic 

 matters which they produce." He recalled that Pasteur had 

 been the first to investigate the action of the toxic products 

 elaborated by the microbe of chicken-cholera. By filtering 

 the culture, Pasteur had obtained a liquid which contained no 

 microbes. Hens inoculated with this liquid presented all the 

 symptoms of cholera. ''This experiment shows us," con- 

 tinued M. Roux, "that the chemical products contained in 

 the culture are capable by themselves of provoking the 

 symptoms of the disease; it is therefore very probable that the 

 same products are prepared within the body itself of a hen 

 attacked with cholera. It has been shown since then that 

 many pathogenic microbes manufactured these toxic products. 

 The microbes of typhoid fever, of cholera, of blue pus, of acute 

 experimental septicaemia, of diphtheria, are great poison-pro- 

 ducers. The cultures of the diphtheria bacillus particularly 

 are, after a certain time, so full of the toxin that, without 

 microbes, and in infinitesimal doses, they cause the death of 

 the animals with all the signs observed after inoculation with 

 the microbe itself. The picture of the disease is complete, 

 even presenting the ensuing paralysis if the injected dose is 

 too weak to bring about a rapid death. Death in infectious 

 diseases is therefore caused by intoxication." 



This bacillus, like that of tetanus, secretes a poison which 

 reaches the kidneys, attacks the nervous system, and acts on 

 the heart, the beats of which are accelerated or suddenly 

 arrested. Sheltered in the membrane like a foe in an ambush, 

 the microbe manufactures its deadly poison. Diphtheria, as 

 defined by M. Roux, is an intoxication caused by a very active 

 poison formed by the microbe within the restricted arec 

 ■^i'herein it develops. 



