THE POISONOUS SNAKES OF INDIA. Ill 



(3) " Hsemorrhagin " is relatively more potent in this than in 

 any other of our Indian snake venoms. In conjunction 

 with 2 (a) it causes profuse bleedings. 



EcHis Toxemia. 



The poison of the saw scaled viper (EcMs cwrinata) has no direct 

 effect upon the central nervous system, except upon the vasomotor 

 centre (as shown by Eogers). Consequently paralysis are conspicu- 

 ously absent, and the chief constitutional symptoms observed are 

 indicative of cardiac weakness. In addition the constitution of the 

 blood is profoundly altered and the blood vessels have their lining 

 membrance damaged with the result that heemon-hages almost always 

 occur. 



The local symptoms are usually very severe. (See page 103). 



In Echis toxaemia the heart labours under great difficulties. Like 

 Colubrine venoms this powerfully depresses the vasomotor centre 

 in the brain, producing a fall in blood pressure, and a weakening of 

 the heart's pulsations in consequence. Fraser and Gunn have also 

 demonstrated a direct weakening effect that this venom exerts on 

 the cardiac muscle itself. By a destruction of the red blood cells an 

 impoverished quality of the blood is supplied to the heart's muscle, 

 which suffers again on this account. Further, the activity of the 

 heart is lowered proportionately to the degree to which haemorrhages 

 occur. Over and above all these influences are the emotional ones, 

 due to anxiety, fright, and pain. It is not surprising therefore that 

 death is due to heart failure. Any attendant tendency to asphyxia 

 that may present itself is brought about indirectly by the cardiac 

 weakness supplying insufficient blood to the respiratory centre, and 

 not by any direct influence on the respiratory centre, in the brain, 

 or on the terminations of the phrenic nerves. 



illustrative Gases, 



No. 1. 



Bite from Echis, 12 inches long. Death in 27 hours. Au.topsy. 



Reported by Captain C. H. Eeinhold, i.M.S., (^Indian Medical 

 Gazette, November 1910). 



