562 



SCIENCE. 



[N. S. Vol. V. No. 119. 



fermentation was tliouglit to be due to a 

 similar cause. It had been known for ages 

 that the juice of the grape, if allowed to 

 stand, underwent changes by which its 

 character was modified and wine was 

 formed, or this change might be allowed 

 to progress further until the juice had been 

 converted into vinegar and finally carbon 

 dioxide gas and water. These alterations, 

 those which take place in the digestive 

 tract of animals and are involved in the 

 conversion of dead animal and plant matter 

 into their simplest constituents, were classed 

 under the general head of fermentations. 



The fermentations, especially that of wine, 

 an Italian chemist, Fabroni, in 1822, sup- 

 posed to be induced by a substance of vege- 

 table origin, but closely allied to the white 

 of egg. He considered this material iden- 

 tical with the gluten of cereals and gave 

 to it the name of the ' principle vegeto- 

 animal.' For nearly forty years after- 

 wards this theory was applied by chemists 

 to all fermentations. It was supposed that 

 the albuminoid substance present exposed 

 to the oxygen of the air experienced a pro- 

 gressively variable alteration, that diverse 

 modifications of matter were produced 

 which constituted the ferments of diverse 

 nature. The fermentation was the result 

 of the molecular movement thus commu- 

 nicated. These theories were based upon an 

 erroneous interpretation of what occurred 

 under certain conditions. There exists in 

 wine, when it is being converted into vine- 

 gar, a substance which acts to bring about 

 this modification, but this is not dead 

 albuminoid matter, but a living plant. 

 This fact the lamented chemist, Pasteur, 

 demonstrated in his careful studies upon 

 the production of wine and its conversion 

 into vinegar. Before this time, it is true, 

 there were many who failed to accept the 

 theory of spontaneous oxidation, and en- 

 deavored to show that if fermentable liquids 

 were boiled in flasks which were then im- 



mediately sealed, the fermentation could 

 not take place. But this did not fulfill the 

 demands of one school of chemists, viz., 

 that plenty of oxygen gas should always be 

 present. When the liquid was boiled in con- 

 tact v/ith air which had previously been 

 drawn through sulphuric acid, it was claimed 

 that the air had undergone some chemical 

 change, so it was not until 1854 that this 

 objection was overcome by previously pass- 

 ing the air in the presence of which boiling 

 took place through cotton, and it was then 

 that this school of chemists found their 

 theories in danger. Pasteur demonstrated 

 that the plant present in the preparation 

 of vinegar was the simplest form of life, a 

 cell which could be easily destroyed by 

 heat. Its presence was absolutely neces- 

 sary for fermentation, and without the liv- 

 ing cell no amount of dead vegetable matter 

 could cause the peculiar molecular disar- 

 rangement which had been claimed. While 

 Liebig had contended that as long as the 

 juice of the grape remained away from con- 

 tact with the oxygen of the air the neces- 

 sary motion could not be imparted to the 

 molecules, which movement subsequently 

 caused the phenomena of fermentation. 

 Thus was brought to an end the strife be- 

 tween the two schools of vitalists and 

 chemists ; the one school of chemists de- 

 manding the presence of ogygen only, the 

 other the presence of a living plant cell in 

 addition to oxygen. From this strife of 

 the two schools was evolved in reality a 

 new science and new theories, which have 

 made the past thirty years marvelous in 

 their explanations of many of the simplest 

 phenomena of plant and animal life and 

 death, placed the practice of medicine upon 

 a scientific basis and rendered possible an 

 intelligent system of agriculture and ani- 

 mal husbandry. 



Pasteur's discoveries also served to explain 

 the true cause of the poisonous properties of 

 spoiled meats and other foods, stagnant 



