482 THE POPULAR SCIENCE MONTHLY. 



that the cause which communicated life to his infusions was not uni- 

 formly diffused through the air ; that there were aerial interspaces 

 which possessed no power to generate life. Standing on the Mer de 

 Glace, near the Montanvert, he snipped off the ends of a number of 

 hermetically-scaled flasks containing organic infusions. One out of 

 twenty of the flasks thus supplied with glacier air showed signs of life 

 afterward, 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 generative power. These and other 

 experiments, carried out with a severity perfectly obvious to the in- 

 structed 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 without the operation of antecedent life. 



The main position of Pasteur, though often assailed, has never yet 

 been shaken. It has, on the contrary, been strengthened by practical 

 researches of the most momentous kind. He has applied the knowl- 

 edge won from his inquiries to the preservation of wine and beer, to 

 the manufacture of vinegar, to the staying of the plague which threat- 

 ened utter destruction to the silk-husbandry of France, and to the ex- 

 amination of other formidable diseases which assail the higher animals, 

 including man. His relation to the improvements which Prof. Lister 

 has introduced into surgery is shown by a letter quoted in his " Etudes 

 sur la Biere." ' Prof. Lister there expressly thanks Pasteur for having 

 given him the only principle which could have conducted the anti- 

 septic system to a successful issue. The strictures regarding Pasteur's 

 defects of reasoning, to which we have been lately accustomed, deliv- 

 ered with a tone of supercilious contempt, where reverent teachable- 

 ness would have been the fitting state of mind, throw abundant light 

 upon their author, but none upon Pasteur. 



Redi, as we have seen, proved the maggots of putrefying flesh to 

 be derived from the eggs of flies ; Schwann proved putrefaction itself 

 to be the concomitant of far lower forms of life than those dealt with 

 by Redi. Our knowledge here, as elsewhere in connection w T ith this 

 subject, has been vastly extended by Prof. Cohn, of Breslau. "No 

 putrefaction," he says, " can occur in a nitrogenous substance if its 

 bacteria be destroyed and new ones prevented from entering it. Pu- 

 trefaction begins as soon as bacteria, even in the smallest numbers, 

 are admitted either accidentally or purposely. It progresses in direct 

 proportion to the multiplication of the bacteria, it is retarded when 

 they exhibit low vitality, and is stopped by all influences which either 

 hinder their development or kill them. All bactericidal media are 

 therefore antiseptic and disinfecting." 2 It was these organisms act- 



1 P. 43. 



2 In Ms last excellent memoir, Cohn expresses himself thus: "Wer noch heut die 

 Fanlniss von einer spontanen Dissociation der Proteinmolecule, oder von einem unorgani- 



