■A 48 VENOMS 



and I was able to show that their standard had not perceptibly 

 deteriorated. It was only the appearance of the contained liquid 

 that was slightly changed ; it was discoloured, and when shaken 

 small white flakes were seen floating through it. These flakes 

 are not a sign of deterioration ; they are composed of deposits 

 of precipitated albumin. They can be partly dissolved again by 

 violent shaking, or they may be separated before use by filtration 

 through sterilised paper. 



In a dry state, antivenomous serum may be kept for an almost 

 indefinite period, in hermetically sealed glass tubes. In this con- 

 dition it is usually divided into doses of 1 gramme, and when it 

 is desired to make use of it, it is sufficient to dissolve a dose in 

 10 c.c. of water which has been boiled and allowed to cool, which 

 takes two or three minutes. This solution is then injected beneath 

 the skin, as though it were liquid serum. 



The Pasteur Institute at Lille prepares in this way large 

 quantities of antivenomous serum, which are sent all over the 

 world to those countries in which poisonous snakes are most 

 dangerous. 



Recently, special laboratories for the production of this prepara- 

 tion have been instituted at Bombay and at Kasauli, in the Punjab, 

 by Drs. G. Lamb and Semple ; at Philadelphia, by Professor 

 McFarland ; at Stio-Paulo, in Brazil, by Dr. Vital Brazil ; and 

 at Sydney, by Dr. Tidswell. 



Specificity and Polijvalence of Antivenomous Serums. — By means 

 of a large number of experiments I have proved that snake-venoms, 

 whatever their origin, contain two principal substances : neuro- 

 toxin, which exerts its effects upon the elements of the nervous 

 system, and hcemorrhagin (Plexner and Noguchi), or proteolytic 

 diastase, the effects of which remain exclusively local when the 

 venom is introduced subcutaneously into the cellular tissue, but 

 which produces coagulation of the blood when the venom is 

 ni cted directly into the blood -stream, 



