256 LOUIS PASTEUR. 



after remaining in the earth for months, and even 

 years. 



These experiments, curious as they were, were 

 only, so to speak, laboratory experiments. It was 

 necessary to investigate what happened in the open 

 country with all the variations of dryness, of damp, and 

 of cultivation. A happy inspiration came to Pasteur 

 and his assistants. They had buried in the midst of 

 summer, in an isolated corner of the farm of St. Ger- 

 main, near Chartres, a sheep which had died of natural 

 splenic fever, and of which they had made the autopsy. 

 Ten months afterwards, and again fourteen months 

 afterwards, the idea occurred to them of collecting 

 some of the earth from this grave. After having ex- 

 amined it, and established the presence of the spores 

 of the microbe, they produced, by the inoculation of 

 guinea-pigs, the splenic disease and death. But the 

 circumstance which deserves the greatest attention, is 

 that the same experiment was successfully made with 

 the earth on the surface of the grave, though this earth 

 had not been disturbed during the interval. Some 

 experiments were afterwards made on the earth of 

 some trenches dug in a meadow of the Jura, where 

 some cows which had died of splenic fever had been 

 buried at a depth of two meters. Two years after- 

 wards, by successive washings of the earth on the sur- 

 face of the graves, deposits w r ere extracted which at 

 once produced splenic disease. At three trials within 



