354 THE SNAKES OF SOUTH AFRICA. 



like gum, but docs not crystallize. The acid, being of a volatile 

 nature, disappears, leaving the dry venom neutral. Venom 

 when properly dried will retain its toxic or poisonous properties 

 a great number of years. Dried venom will readily dissolve 

 in tepid water. When kept in solution in water, snake venom 

 decomposes and loses its poisonous properties in a short time. 

 On the other hand, if venom be mixed with glycerine it will 

 keep indefinitely. Dr. Weir Mitchell kept venom for thirty-two 

 years, and Dr. C. J. Martin for thirteen years without it losing 

 any of its poisonous properties. I have also found that after the 

 lapse of years its effect is just as potent upon animals as when 

 injected fresh. Snake venom is a mixture in variable proportions 

 of proteid substances and salts dissolved in from 65 to 80 per cent. 

 of water. The albumins in snake venom are devoid of poisonous 

 properties. The active principles of venom are proto- and hetero- 

 albumoses. Snake venoms are very complex and varied in their 

 action. The composition, nature, and effects of venoms differ 

 considerably. Pure Puff Adder venom, if allowed to stand in a 

 glass tube, deposits a white fiocculent mass. The rest of the 

 venom becomes light amber in colour and sets to the consistency 

 of jelly a few hours after being drawn from the snake. If mixed 

 with water and stirred, the white precipitate is dissolved. Cobra 

 venom remains in a transparent condition. 



Dr. C. J. Martin, Director of the Lister Bacteriological Insti- 

 tute of London, says : — " The analysis of the physiological 

 action of venoms has proved them to be made up of a great 

 many more constituents than would be imagined from their 

 chemical examination. Different venoms have been found to 

 contain one or more of the following : (i) a powerful fibrin- 

 ferment ; (2) an anti-fibrin ferment ; (3) a proteolytic ferment ; 

 (4) various cytolysins capable of acting upon red blood corpuscles, 

 phagosytes, endothelial cells of blood vessels, nerve cells, and 

 the cells of various other tissues. In addition to the above, 

 various other more remote pathological conditions are induced." 



The various venoms being so different in their combination 

 or " make up," it naturally follows that the venoms of various 

 kinds of snakes would induce symptoms more or less dissimilar. 

 This is the reason the serum from an animal immunized to the 

 venom of only one species of snake fails to act as a sufficiently 

 satisfactory antidote in all forms of snake bite. 



