Wea//ie>\ iratrr and Disease. 21 



microbes. Another important function is, that they prepare 

 soils for vegetable life. A soil that is sterili/.ed or deprived 

 of all its microbes will not afford the proper nourishment for 

 the plants existing on it. 



Another instance of active intervention is that there is a 

 microbe found in ferruginous springs, or stagnant pools, which 

 produces a deposition of an iron salt from this water, and when 

 the microbe dies the deposition stops. 



These facts were, more or less, admitted for sonic lime be- 

 fore the germ theory of disease had been demonstrated in any 

 instance. The growth of confidence in this theory proceeded 

 through different stages of evidence. Guesses and suggestions 

 of its truth had been offered to the public and to the medical 

 profession many times before. Pasteur, a chemist, prepared 

 its first stage by his researches on the different ferments, 

 showing each form of fermentation had its specific form of 

 micro-organism as its cause. It w^as not unnatural to connect 

 disease with a fermentative process in connection with the 

 human or animal bod}'. There resulted active examinations 

 of blood and serum and the animal tissues by different experi- 

 menters. 



Davaine first proved that ])acilli found in the blood of what 

 is called "Splenic Disease" were the cause and not the con- 

 sequence of the disea.se. This was another and important 

 stage, and in very quick succession have followed demonstra- 

 tions of the causal connection of specific microbes in quite a 

 number of diseases. 



A popular audience can not be led through all the elabor- 

 ated and complicated evidence which appeals to a professional 

 or scientific one, but there is a body of knowledge before the 

 public now long enough that ought to be conclusive as to the 

 germ theory of disease. We cite first the case of the disease 

 produced by the Trichina spiralis. This is of the animal 

 kingdom, but microscopic, and its connection with trichinosis 

 in the human subject so often proved, that the public at large 

 has accepted it, and w^e have seen that our Government has 

 been obliged to give it National recognition in its management 

 of our foreign commerce. Another body of knowledge the 

 public have been educated to: that is, the fact of the wonder- 

 ful success in surgical operations and in the prevention of all 



