522 THE POPULAR SCIENCE MONTHLY. 



inces and cities ; while the physiologist insensibly acquires the 

 skill and erudition of the philologist. 



For a long time doctors believed that they had included all the 

 causes of disease in virulent matters, the inclemencies of the 

 atmosphere, abuses of strength and pleasures, and indulgences of 

 passion. The j)art of parasites was regarded as limited and 

 secondary, and of those, animal parasites were regarded as the 

 most important, while vegetable parasites were not supposed to 

 play any appreciable part. During the former half of this century, 

 the most intelligent persons considered botany as a part of natural 

 history, very fit to discij)line the senses and strengthen the under- 

 standing of the future doctor, to cultivate the spirit of observation 

 within him, and to exercise him in the construction of syntheses 

 which would permit him to classify the phenomena. The study 

 of botany was valued only as a gymnastics of the intelligence. It 

 was often forgotten after the first years of study, unless it was 

 modestly called to mind to illustrate the difference between one 

 medicinal plant and another, as parsley and hemlock, or a poison- 

 ous and edible mushroom. Now, behold the whole camp of etiolo- 

 gists and a good part of the camp of anatomo-pathologists press- 

 ing into the minute examination of the lowest plants, most of 

 them belonging to the group of those microscopic fungi which are 

 divided transversely and owe to that division an extremely rapid 

 increase. These fungi are called, on account of the division which 

 they undergo, schizomycetes. In many maladies, and those of the 

 most grave, one of these species of fungus is considered the deter- 

 mining cause of the disease. The schizomycetes are the invisible 

 enemies of the health of man. The chief defense against them is 

 indirect; it consists in taking care that they do not, through 

 hygienic deficiencies, find in the body of man a fertile soil predis- 

 posed to receive and feed them. Hence these invisible enemies 

 have forced the doctor to interest himself in botany, if only to 

 convince himself that the presence of a noxious fungus does not 

 inevitably imply a sentence of death. Botany, therefore, is not 

 only an exercise in education and an auxiliary to medicine, but it 

 is also an integral part of medicine and a fertile source of explana- 

 tions. The unity of botany and medicine is in appearance only on 

 the ground of the infinitely little ; but the economy of all organized 

 nature is really displayed in it, the cycle of life which includes 

 death — death from which life, the true phoenix, perpetually rises 

 again. 



Physics has higher ambitions. Mother of all the sciences, in- 

 cluding metaphysics, and ever young in its indefatigable research, 

 it unites the efforts of a matured experience with those of a legiti- 

 mate boldness. It takes pity on the despair of the chemist who 

 can not catch in his crucible a piece of the glowing shell of the 



