RECENT SCIENCE. 825 



hundreds of years ago ; and it was revived early in our century. 

 But scientific bacteriology is of quite recent creation. It dates 

 from the end of the fifties that is, from Pasteur's researches into 

 the fermentation of beer and wine and Virchow's investigations 

 into cellular pathology. Progress has been very rapid since. 

 We have now numerous works, large and small, devoted entirely 

 to the description and study of the life-history of the microscopic 

 organisms which occasion disease ; and every year brings the dis- 

 covery of some new micro-organism to which some disease, or 

 group of diseases, may be attributed. Cholera, typhoid fever, 

 gastric affections altogether, malaria, and influenza ; tuberculosis, 

 leprosy, and cancer ; diphtheria, measles, and scarlet fever ; rheu- 

 matism, anthrax, small-pox, rabies, and tetanus ; nay, even 

 the poison of the cobra snake,* have been traced to separate 

 microscopical beings. The photograph of each separate bacillus 

 or micrococcus may be found in the text-books ; its manners of 

 life, and very often its modes of reproduction, have been carefully 

 studied, both in the animal body and in artificial cultures ; so 

 also its morbid effects when introduced into the bodies of various 

 animals. True that the general reader is often amazed on learn- 

 ing that such and such a microbe which was introduced a few 

 months ago, as the real cause of influenza or of some other dis- 

 ease, is recognized now as a common inhabitant of the human 

 body, and has nothing to do with the said disease ; while a few 

 months later the real enemy will again be discovered, but will 

 have no more success than its predecessor. But such ephemeral 

 discoveries are simply indicative of an unhappily general tend- 

 ency among modern scientists that of hastening to announce 

 discoveries, and to attach one's name to something new, before 

 the supposed discovery has been submitted to the test of searching 

 experiment. The same tendency prevails in all sciences the 

 only difference being, that the general reader is seldom gratified 

 by the daily press with the discovery of a new chemical " law," 

 or of a new " type " of fossil mammals, while each discovery 

 which deals with disease, ephemeral or not, enjoys a wide pub- 

 licity so soon as it has found its way into a scientific periodical. 

 The very rapidity with which the would-be discoveries of new 

 bacilli are reduced to their real value only proves, on the con- 

 trary, the safety of the methods used by bacteriology for distin- 

 guishing between the seeming and the real causes of disease. 



We may thus safely recognize that science already knows a 

 great number of micro-organisms which are capable, under cer- 

 tain circumstances, of producing certain specific diseases ; and we 



* M. Calmette, in Archives de medeciue navale et coloniale, tnars, 1892 ; referred to in 

 Revue Scientifique, 23 avril, 1892. 



