22 Prof. Pedler on Cobra Poison. [Jan. 17, 



appeared to be very insoluble in water, was administered internally to 

 a chicken, and had no poisonous action ; and the solution containing 

 the excess of platinum salt when injected into a chicken had no action 

 whatever. 



Here, then, was a case in wbich, apparently, the poisonous action 

 of the virus had been destroyed or neutralized, for the albuminous 

 precipitate certainly did not contain more than from one-fiftieth to 

 one-hundredth part of its weight of poisonous material. 



I have endeavoured to obtain a sufficient quantity of the poison to 

 give me enough of the platinum compound for the determination of 

 its composition, but up to the present time I have only succeeded 

 in making one complete analysis ; the numbers which I have obtained 

 are as follows : — 



'2583 gram of platinum compound yielded *3065 gram C0 2 , 

 "0996 gram H 2 and '0418 gram platinum. From this it follows that 

 C == 33*42 per cent., H = 4-28 per cent., Pt. = 16-18 per cent. Also 

 '0946 gram platinum compound yielded *1462 gram ammonia plati- 

 num chloride, therefore, N = 9 '69. per cent. Unfortunately, I have 

 been unable to determine the amount of chlorine, but if the com- 

 pound has the ordinary composition of 01 6 for Pt., the amount of 

 chlorine present would be 17'42 per cent., and we should thus get : — 



By Experiment. 



Calculated for formula PtCl 4 

 (C 17 H 25 N 4 7 HC1) 2 



Chlorine by calculation. . 17 "42 „ 

 *Oxygen by difference .... 19 "01 „ 



16 "36 per cent. 



17 -65 



33 -81 „ ■ 

 4 31 „ 

 9 29 „ 



18 -58 „ 



Judging from such insufficient data, it would be impossible to assign 

 with certainty any formula to this compound. It will be seen that 

 I have appended the percentage composition calculated for PtCl 4 

 (CnH 23 N 4 7 HCl) 2 ; but, of course, I do not imagine that I have as- 

 certained the true formula of the poisonous principle ; I merely throw 

 it out as a suggestion that its composition may be something near 

 C 17 H 25 ¥ 4 7 , or the double of this. 



From the experiment described above, it will be seen that the addi- 

 tion of the solution of platinum tetrachloride caused a marked change 

 in the physiological action of the poison; and it should be borne in 

 mind, that my main object in these experiments was the discovery of 



* Only the faintest traces of sulphur are present in the compound. 



