THE CURATIVE POISON 127 



which had died of anthrax the preceding year. 

 Pasteur, who always examined things closely, 

 noticed on the surface of the soil a multitude of 

 little lumps of earth thrown up by earth- 

 worms. The idea then occurred to him that in 

 their continuous journeyings from the lower 

 depths to the surface the worms carried above 

 ground some of the soil rich in the humus that 

 surrounded the dead bodies, and along with it 

 some of the spores of anthrax which it con- 

 tained. But Pasteur never stopped short at 

 conjectures. He immediately passed on to ex- 

 periments. These justified his expectations: 

 the earth contained in one of the worms, when 

 used to inoculate guinea-pigs, produced anthrax 

 in them." (Roux, L'ceuvre medicate de Pas- 

 teur, Agenda du Chimiste, 1896.) 



Pasteur had studied first the active cause of 

 the disease, and next its mode of propagation, 

 and found that the spores penetrated into the or- 

 ganism of the animals, sheep or cattle, through 

 the mucous membranes of their mouths, where 

 they were torn by the dry and prickly grass. 



