Tkaverb. — On Pathogenic Microbes. 57 



the disease, and died. The glands and tissues of the back of 

 the throat were found to be in the condition which would 

 naturally result from inoculation by means of wounds, slight, 

 it might be, of the surface of the mucous membrane of the 

 mouth, and, in order to ascertain whether this was the likely 

 cause, grass mixed with thistles, bearded ears of barley, and 

 other prickly forms of fodder, on which bacteridia had been 

 scattered, was given to other sheep, the result being that mor- 

 tality amongst them was rapidly induced. 



Experiments were then made in order to ascertain how 

 long the vitality of the bacteria was maintained after the 

 death of an infected animal, and it was found that, while by 

 far the greater number were destroyed by the putrid fe}'- 

 mentation of the carcases of the diseased sheep, a proportion 

 became disengaged by the gas generated during decomposition, 

 and that these, drying up, produced spores which retained 

 their vitality for a long period, and were so minute and light 

 as to be capable of lieing transported by even the weakest 

 currents of air. 



As regards the human subject, it has been found that 

 anthrax, appearing in the first instance in the form of malig- 

 nant pustules, affects shepherds, butchers, tanners, and others 

 who handle the flesh and skins of tainted animals, the disease 

 usually resulting rapidly where there is any scratch or wound 

 in the face or hand. 



Instances have occurred in which the disease has appa- 

 rently been introduced into man through the mouth or lungs, 

 but human beings are apparently less subject to contract it 

 in this manner than the herbivora, for the flesh of animals 

 killed after the microbe has become fully developed in the 

 blood is often eaten with impunity in the farmhouses on pro- 

 perties on which the disease has been prevalent. It may, 

 however, be said that in this case the microbes are effectually 

 destroyed by the cooking processes to which the flesh is sub- 

 jected. 



The important researches which were induced by and fol- 

 lowed upon the discovery of the effects of the inoculation of 

 sheep with Bacillus anthracis have, as already mentioned, 

 clearly demonstrated that nearly if not all the most serious 

 febrile diseases which attack man and the domestic animals 

 have their origin in the introduction into the system of special 

 forms of microbes. 



This has been established in the cases (amongst others) of 

 cholera, typhus, and typhoid fevers, small-pox, recurrent, 

 yellow, scarlet, and intermittent or malarious fevers, and in 

 croup, and also in such minor diseases as measles, whooping- 

 cough, kc, in man, and in the cases of the rouget, or swine- 

 fever, of glanders as affecting horses, of rabies as affecting the 



