SPONTANEOUS GENERATION. 301 



periments of Schroeder and Von Dusch. He showed 

 that the cause which communicated life to his infusions 

 was not uniformly diffused through the air ; that there 

 were aerial interspaces which possessed no power to 

 generate life. Standing on the Mer de Grlace, near the 

 Montanvert, he snipped off the ends of a number of 

 hermetically sealed flasks containing organic infusions. 

 One out of twenty of the flasks thus supplied with 

 glacier air showed signs of life afterwards, while eight 

 out of twenty of the same infusions, supplied with the 

 air of the plains, became crowded with life. He took 

 his flasks into the caves under the Observatory of Paris, 

 and found the still air in these caves devoid of genera- 

 tive power. These and other experiments, carried out 

 with a severity perfectly obvious to the instructed 

 scientific reader, and accompanied by a logic equally 

 severe, restored the conviction that, even in these lower 

 reaches of the scale of being, life does not appear with- 

 out the operation of antecedent life. 



The main position of Pasteur has been strengthened 

 by practical researches of the most momentous kind. 

 He has applied the knowledge won from his enquiries 

 to the preservation of wine and beer, to the manufacture 

 of vinegar, to the staying of the plague which threatened 

 utter destruction of the silk husbandry of France, and 

 to the examination of other formidable diseases which 

 assail the higher animals, including man. His relation to 

 the improvements which Professor Lister has introduced 

 into surgery, is shown by a letter quoted in his Etudes 

 sur la Biere. 1 Professor Lister there expressly thanks 

 Pasteur for having given him the only principle which 

 could have conducted the antiseptic system to a suc- 

 cessful issue. The strictures regarding defects of 

 reasoning, to which we have been lately accustomed, 

 1 P. 43. 



