506 Chapter XVI 



some method of fighting against the poisoning after the patient 

 had been bitten. Thus, we find that many primitive races make use 

 of various methods of immunising the body against the action of 

 [529] venom. The Portuguese colonel, Serpa Pinto ^, in a letter addressed to 

 d'Abbadie, describes the method by which he was vaccinated by the 

 Vatuas, natives of the east coast of Africa. These savages extract 

 the poison of snakes and prepare from it, by the addition of vegetable 

 substances, a very brown glutinous paste which they introduce into 

 incisions made in the skin. This operation is very painful and is 

 followed by a swelling which lasts for a whole week. The Yatuas 

 assert that this method confers a sure immunity against the venom. 

 Serpa Pinto was never bitten by a snake, but, a short time after 

 he had been vaccinated, he was stung, in the Seychelles Islands, by 

 a scorpion without experiencing any ill effects. This experience 

 confirms the assertion of the Vatuas, because it has been shown that 

 the vaccine against snake venom is also efficacious against the bite 

 of scorpions. The fact that after being stung by another scorpion 

 ten years later Serpa Pinto was so ill that for eight days he believed 

 that he was going to die or at least to lose an arm, shows that he did 

 not enjoy natural immunity, and the innocuousness of the previous 

 bite must therefore be attributed to a vaccination the efiect of which 

 had disappeared at the end of ten years. 



Another vaccinal method used by primitive races is that against the 

 pleuropneumonia of the Bovidae. De Rochebrune^ points out that 

 the Moors and the Pouls of Senegambia have "a custom whose 

 origin is lost in the obscurity of antiquity" which consists in the 

 inoculation into their herds of cattle of the virus of the epizootic 

 pleuropneumonia. "The point of a knife of primitive form, or of 

 a dagger, is plunged into the lung of an animal that has died from 

 the disease and an incision, sufficient to allow the virus to penetrate 

 below the skin of the healthy animal, is made into the supranasal 

 region. Experience has demonstrated the success of this protective 

 operation." 



In Europe, the vaccinations of cattle with the viras of pleuro- 

 pneumonia have certainly been known for more than a century, for, 

 in a pamphlet published at Berne in 1773^ mention is made of the 

 "inoculation" of Bovidae as a means of preventing the disease in 



1 Compt. rend. Acad. d. sc, Paris, 1896, t. cxxii, p. 441. 



2 Compt. rend. Acad. d. sc, Paris, 1885, t. c, p. 659. 



3 This pamphlet has been reprinted in the Rec. de med. vet., Paris, 1886, p. 624. 



