SUMMING UP. 75 



chemical changes of vinous fermentation are caused by the 

 life and growth of this plant. They disproved, by experiment, 

 the previous hypothesis, that oxygen is the active agent in any 

 of the similar processes ; and, reasoning from this discovery, 

 came to the conclusion that all the fermentations, decompo- 

 sitions, miasms and contagions were caused by the life force. 



4th. These conclusions were attacked by chemists, notably, 

 by Professor Liebig, who denied both the facts claimed and 

 the conclusions arrived at, since which time there has been a 

 continuous discussion of the subject. 



5th. In 1854, Schroeder conclusively disproved the exist- 

 ence of gaseous ferments claimed by chemists, by admitting 

 air filtered through cotton batting to sterilized fluids without 

 causing fermentation. 



6th. From 1857 to 1861 Pasteur successfully worked out 

 all the more ordinary fermentations by his fractional flask 

 cultivations, and proved each of them to have a specific plant 

 growth as its cause. He also showed that none of the decom- 

 positions could proceed without living organisms, though the 

 specific organism belonging to each was not clearly made out. 



7th. Basing his efforts on the results of the last two, Mr. 

 Lister introduced his antiseptic treatment of wounds, in 1865, 

 which has proved a panacea for most of the dreaded in- 

 fectious wound troubles in all hospital surgical practice. 



8th. M. Pasteur, Dr. Koch and others have succeeded in 

 isolating a number of distinct disease-producing germs, and 

 causing the specific diseases in animals, regularly, by planting 

 these germs under the skin, and Dr. Koch, especially, has 

 succeeded in doing this after freeing the organisms of all 

 possible following of decomposing matter by growing them 

 upon dry slides. 



9th. This much having been proven, the continued obser- 

 vation of numerous other organisms of distinct form and 



