106 LOUIS PASTEUR 



Various infusions were poured through the fun- 

 nel tube into the test tubes and brought to a boil 

 by a burner placed below them. Similar sets of 

 tubes, filled with the same material, were boiled for 

 the same length of time and exposed to ordinary- 

 air as a control experiment. In the one case the 

 tubes were protected from floating matter, in the 

 other they were exposed to it. Otherwise the con- 

 ditions in the two sets were the same. 



Hundreds of experiments were tried with all sorts 

 of substances; urine, infusions of beef, haddock, 

 sole, codfish, hare, grouse, liver, oysters, turnips, 

 hay, and many other materials in varying degrees 

 of strength. Tyndall was nothing if not thorough. 

 And what was the outcome? "There is no shade 

 of uncertainty," says Tyndall, "in any of the re- 

 sults. In every instances we have within the 

 chamber perfect limpidity and sweetness — without 

 the chamber, putridity and its characteristic smells. 

 In no instance is the least countenance lent to the 

 notion that an infusion deprived by heat of its 

 inherent life, and placed in contact with air cleansed 

 of its visibly suspended matter, has any power 

 whatever to generate life anew." 



The hay infusion employed had been heated to 

 i2o° C. for four hours as the spores of the hay 



