CHAPTER XXIII 



CONTROL OF BACTERIAL DISEASES 



Aristotle (384-322 n.c.) instructed Alexander the Great to have his sol- 

 diers boil their water in order to prevent epidemics of disease in camps. 

 Possibly to this bit of practical biology Alexander owes his conquest of 

 the world. 



Advertendum etiam, siqua erunt loca palustria, et propter easdem causas, 

 et quod (arescunt) crescunt animalia quaedam minuta, quae non possunt 

 oculi consequi, et per aera intus in corpore per os ac nares perveniunt atcjue 

 efficiunt difficilis morbos.i — Vakro (b.c. 110-27), '' De He Rustica," Lib. I, 

 11-12 (Keil, 145) 



Already in his studies on silkworms, Pasteur's first experience in the 

 domain of disease, the dawn of a new era in the contest of man with con- 

 tagion opens up before him. He says: "II est au pouvoir de Thomme 

 de faire disparaitre de la surface du globe les maladies parasitaires, si, 

 comme c'est ma conviction, la doctrine de la g^n^ration spontan^e est une 

 chim6re."2 — Fkanklaxd, ''Life of Pasteur,"' p. 123 



Bacteria and disease. The majority of bacteria are harm- 

 less or beneficial. A few are venomous, as are a few species 

 of snakes, fishes, trees, or mushrooms. The venomous bac- 

 teria strike plants, animals, and man just as really as do lead 

 bullets, and wound and kill in essentiallv similar wavs. The 

 notion is current that bullets hit the fittest, while l)iR'teria 

 seek out the untit, but tliere is not nuich ground for this 



1 "One should be on guard, if there should be any swampy places, both 

 for the same reasons and because there grow certain minute animals, which 

 the eyes cannot perceive, and which, permeating the air, enter the body 

 through mouth and nostrils and cause serious diseases." — Professor S. F. 

 DiNN, Lniversity of Oregon, Translator 



2 '' It is within the power of man to cause to disappear from the surface 

 of the globe the parasitic diseases, if, as is my conviction, the doctrine of 

 spontaneous generation is a chimera.'' 



231 



