THE DISCOVERY OF ANTHRAX 5 



appear where their germs are already present, and it is 

 sufficient to exclude these germs if their intrusion is to be 

 prevented. 



The great discovery was made by Davaine, in 1863, of 

 the bacillus of anthrax in the blood of animals suffering 

 from splenic fever. This year will be ever memorable in 

 the annals of medicine, on account of the fact that this is 

 the first notice of a specific organism in connection with 

 disease. This opened the way to the many brilliant dis- 

 coveries which from then have taken place almost year by 

 year, and have thrown so much light upon the cause and 

 prevention of disease. The mysterious veil which for many 

 centuries has hung over some of the most widespread and 

 terrible of the diseases which afflict the human race is being 

 gradually drawn aside. 



In 1873 Obermeier described the spiral organism which 

 bears his name, in the blood of patients suffering from 

 relapsing fever. Hansen in 1879 described the bacillus 

 of leprosy. In 1880 Eberth discovered the typhoid bacillus, 

 which was artificially cultivated by Gaffky in the following 

 year. Koch in 1881 devised his beautiful method of 

 using solid culture media, which is now so universally 

 used. He thickened nutrient meat-broth with gelatine, 

 whereby the organisijis inoculated into the liquid are fixed 

 ill situ when it cools and sets, thus rendering it easy to 

 obtain pure cultures of any micro-organism by picking out 

 a fragment of a colony and planting it on a fresh surface. 

 Lbffler in 1882 discovered the organism of glanders. In 

 1883 Nicolaier described and investigated the bacillus of 

 tetanus, and Koch the bacillus of tubercle. Koch, again, 

 in 1884 published his discovery of the spirillum of Asiatic 

 cholera (Koch's comma bacillus), while, perhaps, the latest 

 discovery is that of the bacillus of influenza in 1892 by 

 Pfeiffer. 



