Semi-Centennial Volume. 27 



produces an antibody — an antienzyme — for certain proteins present in 

 the typhoid bacili, and in the organism or whatever it may be that causes 

 smallpox. 



The technique and subject matter of the science has now become so 

 broad and complicated that in it, as in many other sciences, it is neces- 

 sary to specialize along many different lines, and of course there is no 

 probability that the end is near. 



The influence of the science is now felt in numerous paths of activity, 

 and naturally it invokes the aid of many other branches of learning. 

 Its greatest influence is probably exerted in medicine, but it likewise 

 furnishes much of the subject matter in other professions or occupations. 

 Only a few of these will be named. 



In agriculture we see that the richness of the soil is due to the decay 

 of organic substances, and that this is brought about in the main by 

 bacteria. We know that the destruction of these things is often decidedly 

 unwelcome, but it is, nevertheless, a beneficent and entirely necessary 

 process. Otherwise the needful elements, such as nitrogen, stored up in 

 the bodies of plants and animals, would very tardily be again available 

 for our use. Nature would then be a genuine miser, taking the neces- 

 sary elements of life and activity out of circulation. It is thus seen that 

 our very life is dependent upon death and decay. Again, bacteria add 

 nitrogen to the soil from the great ocean of it in the air. Others help to 

 render certain substances available for plants. Sulphur, phosphorus 

 and others are included in this list. But others, like the Prodigal Son, 

 are ready to waste the needful substances of the soil, and will do so if 

 not controlled. These facts added to others, such as the loss of living 

 plants and animals and various farm products, bring the farmer face to 

 face with the necessity of an understanding of bacteria. 



This leads us to a realization of the fact that man from time imme- 

 morial has had to struggle to keep foods obtained in excess of need at 

 certain times or places to the time or place in which the order of need 

 and acquirement shall have changed places. Bacteria of decay have 

 largely been the occasion of this, and our great canning and other food- 

 preserving industries are the result. It is quite evident that man was in- 

 tended to live by the sweat, not only of his brow, but of his intellect as 

 well. 



We are led further again, this time to see a connection between bac- 

 teriology and commerce. The thousands of refrigerator cars will illus- 

 trate our point. Quarantine regulations against bubonic plague and 

 Texas fever are others. Our experience with foot-and-mouth disease is 

 quite fresh in memory. 



The principles of bacteriology have had a great influence on hygiene 

 and sanitation, and these subjects consist largely now of rules, the need 

 for which was made apparent by the facts of this science. These again 

 ramify through all of the avenues of life. They may be said to reach 

 from one extreme to another — all the way from the drainage of land, 

 the construction of buildings of all sorts, to the sentiments expressed 

 in kissing. They range from table etiquette to the disposal of sewage; 

 from even before the birth of a child to the disposal of the body after 



