238 GENERAL THERAPEUTICS FOR VETERINARIANS 



1. Vaccination Accokdinq to Pasteur. — The &st protective vaccina- 

 tions were made in 1880 by Toussaint, who heated defibrinated anthrax blood 

 at 50-55° C. for 10 to 15 minutes and then used it immediately as a vaccine. 

 Pasteur demonstrated in 1881 that immunity could be produced by attenu- 

 ating the bacilli. Further investigations showed that the virulence of the 

 anthrax bacilli could be reduced by very numerous and different methods: 

 heat (Pasteur, Toussaint, Chauveau), compressed oxygen (Chauveau and 

 Wosnessenski), antiseptics (Chamberland and Roux), sunlight (Arloing). 

 The bacilli can also be weakened by cultivating them upon the blood of vacci- 

 nated sheep (Metschnikoff) or in the bodies of frogs (Lubarsch). Pasteur 

 produced his vaccine by cultivating the bacilli at 42-43° C. in an atmosphere 

 of oxygen for 24 days for the first or weaker vaccine and for only 12 days for 

 the second or stronger vaccine. The animal is first vaccinated with the first 

 vaccine and 10 to 14 days later with the second vaccine. The technique of the 

 vaccination according to the Pasteur method is as follows: The vials sent 

 out from the Pasteur laboratory must be used at once, the entire contents 

 beiag withdrawn at one time; they must not be opened until immediately 

 before the vaccination. A syringe holding one gram and divided into eight 

 divisions is used to make the injections. Each time before being used the 

 B3rringe must be carefully cleaned and disinfected. The lymph vial contain- 

 ing the first vaccine is thoroughly shaken, opened and the sjringe filled 

 directly from it. One-eighth of the contents is then injected subcutaneously 

 on the inner side of the right thigh of the sheep to be vaccinated, and the open- 

 ing made by the needle is closed with the thumb. After 12 to 14 days, the 

 second vaccination is made with the second vaccine in the same maimer. 

 One-fourth of the contents of the syringe is injected in vaccinating cattle, 

 the first vaccine being injected in back of the right shoulder and the second 

 vaccine in back of the left shoulder; the hair is clipped before the injection 

 is made. Cows in advanced pregnancy and lambs and calves should not be 

 vaccinated. 



The results of the Pasteur vaccination are as follows: For sheep it is 

 not to be recommended. Very frequently it produces, especially in sheep, 

 only a very slight immunity or none at all, and in the most favorable cases 

 the immunity lasts only one year, so that it is necessary to vaccinate yearly. 

 Moreover, the mortaUty resulting from the vaccination is often very great, 

 sometimes amounting to 10 to 15 per cent, after the second vaccination. 

 The Pasteur vaccines are also very inconstant, being at one time too strong 

 and at another too weak, according to whether they have been kept at a tem- 

 perature nearer to 42 or 43° C. Sometimes the vaccine shows a return of 

 virulence, especially when it has been attenuated quickly at a high tempera- 

 ture; on the other hand, the virulence may be entirely lost when the vaccine 



