PRINCIPLES OF VETERINARY SURGERY 145 



debt-ed to Pasteur, but not for the secret he withheld in re- 

 gard to the manufacture of anthrax vaccine. The vaccina- 

 tion, as carried out under their direction, consists of two 

 separate inoculations. First with a weak virus, and then, 

 some days after, with a more virulent one. This is known 

 as the double vaccine. A single vaccine is also furnished 

 which is said to impart equal protection against infection. 

 The claims of Koch and other Germans that Pasteur's vac- 

 cine did not protect animals against intestinal infection is 

 probably not true, as years of use seem only to prove the 

 universal benefit of the vaccination. 



Serum Therapy. — The antitoxic serum recommended by 

 Ogata in 1890 has not been adopted, although he proved that 

 such a substance could be produced. The greater prac- 

 ticability of the protective inoculation of Pasteur has ap- 

 parently stopped all researches along that line. 



Field Diagnosis. — In the field anthrax must be dififeren- 

 tiated from other acute disease having a galloping course 

 and termination.. These are malignant oedema, sympto- 

 matic anthrax, tick fever, corn-stalk diseases, etc. The dif- 

 ferentiation is made by the clinical symptoms, by the post- 

 mortem appearances of the blood and organs, and by a bac- 

 teriological investigation. The anthrax carcass has a char- 

 acteristic engorgement of the spleen and an infiltration of 

 the internal organs, and a characteristic darkness of the 

 blood. These are seldom combined in other diseases. When 

 a bacteriological diagnosis is desired, a piece of an ear is 

 taken to the laboratory in a closed jur. An ear will not read- 

 ily decompose, and contains sufficient blood for the purpose. 

 Putrefaction of the specimen greatly interferes with the in- 

 vestigation. 



6. BACILLUS ANTHRACIS SYMPTOMATICI.— 

 This bacterium is the specific causative agent of the disease 

 known under the various names of anthrax bacteridian. 



