98 LOUIS PASTEUR. 



cause of his error ; this is what has vitiated his whole 

 arrangement.' 



Pasteur then instituted experiments exactly similar 

 to those of Pouchet, but taking care to remove every 

 cause of error which had escaped the latter. He em- 

 ployed a glass bulb with a long neck, which he bent, 

 and connected with a tube of platinum placed in a 

 furnace, so that it could be heated nearly to redness. 

 In the bulb he placed some very putrescible liquids 

 urine for example. When the furnace which sur- 

 rounded the platinum tube was in action, Pasteur 

 boiled the liquid for some minutes, then he allowed it 

 to cool, keeping the fire around the platinum tube 

 still active. During the cooling of the bulb the ex- 

 ternal air was introduced, after having first travelled 

 through the red-hot platinum tube. The liquid was 

 thus placed in contact with air whose suspended 

 germs were all burnt up. 



In an experiment thus carried out, the urine 

 remains unchanged it undergoes only a very slight 

 oxidation, which darkens its colour a little but it 

 exhibits no kind of putrefaction. If it be desired to 

 repeat this experiment with alkaline liquids, such as 

 milk, the temperature must be raised a little above 

 the boiling point a condition easily realised with the 

 apparatus just described. It is only necessary to 

 connect with the free extremity of the platinum tube 

 a glass tube bent at right angles, and to plunge the 

 latter to a depth of some centimeters into a basin of 



