1024 TliAXSACTIOXS OF THE AMERICAN INSTITUTE. 



diseases. This power of a body undergoing change, producing 

 change in a body in contact with it, but with which it has no 

 chemical relations, is well known to the chemist. For a better name 

 he calls it the catalytic force. What the force is, or how produced, 

 is not known. The fact is certain, but the explanation of its action 

 is yet to be discovered. In illustration of this theory we may take 

 yeast, which is supposed to be a body undergoing decay. If we put 

 it into a solution of sugar, by its catalytic action it breaks up grape 

 sugar into alcohol, carbonic acid and water. If the amount of yeast 

 is small but little of the sugar will be decomposed, and sweetened 

 water, containing alcohol and carbonic acid, will be left. If the 

 amount of yeast is large, all the sugar will be destroyed. So with 

 malaria. When it enters the blood, through the lungs, it breaks up 

 or alters some of the constituents of the blood by its own change. 

 If the amount is small, but little in quantity, the effect is not seri- 

 ous, but when of great intensity, tlie result is serious if not fatal. 



The otlier theory, called the germ theory, of which Pasteur is per- 

 haps the originator, considers malaria as germs or spores of micro- 

 scopic animals or plants. So all spontaneous changes nearly are, by 

 this theory, caused by microscopic animals or plants. The various 

 fermentations are caused, by as many varieties of these living organ- 

 isms. Putrefaction is the result of the same agency. This theory 

 has received the most energetic development, and its advocates have 

 spared no labor in its investigations, and they consider it, by many 

 recorded experiments, to be fully established. They have found the 

 plant that produces chills and fever and have innoculated healthy 

 persons in healthy districts with the germs, and produced M'hat we 

 might call artificial chills and fever. We have no prejudice against 

 the theory, and if facts can establish it, we readily yield our assent; 

 but they must be of a different character from any we have seen 

 recorded. Dr. Saulsbury, of Cleveland, Ohio, deserves great credit 

 for his persevering and laborious investigations. No one who has 

 investigated tlie subject will deny the presence of germs in malaria, 

 and tlieir presence vitiates our determination of the chemical consti- 

 tution of malaria. No one will deny any of- the facts he has stated ; 

 but when he comes to assert that the germs produced the chills, the 

 very point which we wanted, certainly, he fails to give us satisfac- 

 tion. He did not eliminate from his masses of earth all except the 

 " ague palmella," and hence he fails to show that they were the cause 

 of the induced disease. 



