480 REPORT OF NATIONAL MUSEUM, 1893. 



hours with all the symptoms of viper-bite poisoning. Having thus 

 determined that there exists in the blood of the Natrix a poisonous agent 

 in at least as great a quantity as in the viper and that the immunitj^ 

 of these snakes also is due to this cause, the question naturally arose 

 as to the origin of the venom in the " harmless" snakes — in other words, 

 by which organs is the venom furnished to the blood. Successive inoc- 

 ulation of organic extracts of the principal intestines, liver, pancreas, 

 spleen, thymus, thyroid body, and salivary glands g .ve the result 

 that only those of the latter had any eftect at all and that this effect 

 showed the characteristics ot viper- venom poisoning. The natural 

 conclusion is that the presence of venom in the blood of the harmless 

 snakes is due to internal secretion of the salivary glands.* 



The authors referred to had now reached the stage when they could 

 look around for a suitable attenuation of the venom in order to secure 

 a proj)er "vaccine," and they found that heat had this effect. Some of 

 the results obtained by them by heating are not new — for instance, that 

 boiling tlie viper venom for a few seconds affects it in such a way as to 

 disassociate from it the local phenomena, the uiidestroyed ijortion left 

 being practically elapid, or cobra, poison. When the authors there- 

 fore heated a lethal dose of viper A^enom and, after cooling, inoculated 

 it into a guinea pig, they did practically nothing but inoculate the 

 animal with a much reduced, nonfatal dose of cobra venom. The result 

 of their experiments shows that this vaccination with the thus attenu- 

 ated venom results in a certain amount ot immunity, t 



Naturally the authors next experimented with a view to ascertain 

 the effects of the blood of the animals thus vaccinated. The experi- 

 ments demonstrated the presence of the venom in the blood serum 

 after three days (21st to 24th of January), and that this blood serum 

 also possesses vaccinating properties.! Of course, the results having 

 been published on February 12, sufficient time had not lapsed to deter- 

 mine if the immunity thus obtained is lasting. The authors seem to 

 be hopeful of obtaining such modifications of the blood as will enable 

 them to utilize it as a therapeutic agent. Experiments and time alone 

 will show. 



It is but fair to add that Dr. Calmette claims priority for the dis- 

 covery of the ''serum" vaccine treatment. § 



* Sur la presence de glandes venimeuses chez les Couleuvres, et la toxicity du sang 

 de ces animaux. Compt. Rend. Ac. Sc. Paris, cxviii, No. 2, Jan. 8, 1894, pp. 76-72. 



t Attenuation du venin de la vipere par la chaleur et vaccination dvi cobaye contre 

 ce venin. Compt. Rend. Ac. Sc. Paris, cviii. No. 6, Feb. 5, 1894, pp. 288-291. 



tSur la propriete antltoxique du sang des animaux vaccinas centre le venin de la 

 vipere. (Compt. Rend., Ac. Sc, Paris, cxviii, No. 7, Feb. 12, 1894, pp. 356-358.) 



§ See Henry J. W. Dam. Inoculation against Snake Poison. Dr. Calmette's Experi- 

 ments at the Pasteur Institute, Paris. McClure's Magazine, iii, October, 1894, pp. 

 460-468. 



