428 MICROORGANISMS 



494. Results of Anthrax Vaccination. In 1894, after the 

 anjhrax vaccine had been in use for twelve years, Professor 

 Chamberland, who had been made responsible for the produc- 

 tion of the vaccine, reported that 3,296,815 sheep and 438,824 

 cattle had been vaccinated in France with a mortality due to 

 the vaccination, of only about 1 per cent, for sheep and of 

 0.34 per cent, for cattle. At that time, it was estimated that 

 the average annual loss from anthrax among unvaccinated 

 sheep was 10 per cent, and among unvaccinated cattle was 5 

 per cent. You can see by this that this single discovery by 

 Pasteur has been, and will be for all time to come, of enormous 

 value to stock raisers throughout the world. Vaccination 

 of cattle and sheep and sometimes of other animals is now 

 regularly practised in all countries where the disease has oc- 

 curred. This includes practically all countries in which cattle 

 and sheep are raised. 



VACCINATION AND SMALLPOX 



You are familiar, in a way, with vaccination against small- 

 pox. Since the principle involved in this is essentially the 

 same as that in vaccination against anthrax or any other dis- 

 ease, a little discussion of smallpox vaccination will serve to 

 make the process clearer to you. 



495. The Origin of Smallpox Vaccination. Prior to about 

 the year 1800, smallpox was an extremely common disease. 

 It was so very common that few people escaped having it 

 sometime during life, and it has been estimated that fifty 

 million people died of it in Europe during the eighteenth 

 century. In the early part of this century, it was discovered 

 that, if a little of the pus taken from a patient suffering with 

 the disease is injected under the skin of a healthy person, a 

 mild form of the disease generally results, and that this has 

 the same immunizing result as a more virulent attack of the 

 disease which might be contracted in some natural way. This 

 practice was introduced into England in the year 1717 and for 



