Vaccination 113 



sometimes disastrous because of the general inattention to 

 the quality of the materials used, the mode of inserting them, 

 the condition of the patient's skin, and the careless treat- 

 ment of the resulting lesions. When human virus was used, 

 the transmission of human diseases, such as syphilis and 

 erysipelas, occasionally took place ; now these are rare acci- 

 dents indeed. When no attention was paid to the quality of 

 the bovine virus, and no governmental inspection of labor- 

 atories required, the accidental contamination of the virus 

 occasioned a small number of accidental infections of the 

 patients' arms, but these evils are becoming less and less as 

 greater attention is given to the details of the process. 

 Some accidents and some few deaths there will probably 

 always be, just as there are occasional accidents and occa- 

 sional fatal results following all kinds of trivial injuries, 

 though care will eliminate them as the sources of accident 

 are better understood. 



3. Pasteurian vaccination or bacterination: Although the 

 word vaccination is derived from the Latin vacca, " a cow," 

 and was first employed in connection with Jenner's method of 

 introducing virus modified by passage through a cow, Pasteur, 

 in honor of Jenner, applied it to every kind of protective 

 inoculation, and the word bacterination is only introduced for 

 the purpose of indicating certain differences in the method. 



In 1880 Pasteur* observed that some hens inoculated 

 with a culture of the bacillus of chicken cholera that had 

 been on hand for some time did not die as was expected. 

 Later, securing a fresh and virulent culture, these and 

 other chickens were inoculated. The former hens did 

 not die, the new hens did. Quick to observe and study 

 phenomena of this kind, he investigated and found that 

 when chickens we're inoculated with old and non-virulent 

 cultures they acquired immunity against virulent cultures. 

 This led him to the recommendation of the employment of 

 attenuated cultures as vaccines against the disease, and to the 

 achievement of great success in preventing epidemics by 

 which great numbers of the barnyard fowls of France were 

 being destroyed. 



In 1 88 1 Pasteur,! m experimenting with Bacillus anthracis, 

 observed that if the organism were cultivated at unusually 

 high temperatures it lost the power of producing spores, and 



* "Compte rendu de la Soc. de Biol., 1880, 239; 315 et seq. 



t " Compte rendu de la Soc. de Biol. de Paris," 1881, xcn, pp. 662-665. 



