FERMENTS, FERMENTATIONS, AND LIFE. 273 



tious disorders, and, if in many cases their relation to these 

 disorders is only that of concomitants, in others their 

 relation of causality is very clearly ascertained. Thus 

 Davaine's investigations prove that the maladies called 

 carbuncular, so formidable in men and animals, are due to 

 the excessive development of a species of bacteria in the 

 blood. Typhoid fever also seems to acknowledge a cause 

 of the same kind. Rabbits die from inoculation with blood 

 taken from men attacked by this disease. Our knowledge 

 upon this difficult subject, it must be owned, is very little 

 advanced, in spite of the ardent labors devoted to its ex- 

 tension in the past few years. The illusions of the mi- 

 croscope and the exaggerations of a spirit of routine too 

 often impair the value of studies undertaken in this direc- 

 tion. Without going so far as does the opinion of those who 

 attribute all these disorders to microscopic corpuscles, and 

 regard all morbid phenomena as fermentations, it may at 

 any rate be admitted that these corpuscles, diffused through- 

 out the air, take an important place among the eternal 

 enemies of health. At all times surgeons and physicians 

 have recognized the danger from penetration of common air 

 into the interior of the organism, by the way of wounds or 

 otherwise. We now understand the explanation of the 

 danger. It is not the gases of the air that are dangerous ; 

 but the proto-organisms contained in that fluid must be 

 charged with the fatal influence it exerts in traumatic cases, 

 and putrid infection has no other origin. Thus the anxiety 

 of practitioners now is to protect wounds from access by 

 the germs in the air, by means either of impermeable coat- 

 ing or of antiseptic dressings containing alcohol or phenic 

 acid, or by pneumatic closing up, or by filtration of the air 

 itself through cotton. Under the influence of ideas dis- 

 tinctly introduced into science by the researches we have 

 just reviewed, several practices in surgery have undergone 

 great modifications. 



