THEIE NATTIEE AND EFFECTS. 133 



But it can be proved that though cobra-poison, when 

 mixed with a caustic alkali, produces no symptoms, 

 yet it has not permanently lost its poisonous properties, 

 as they can be restored to it. 



Experiment VIII. 



A quantity of fresh cobra-poison from several cobras 

 was taken. It was found that one quarter of a cubic 

 centimetre of this poison killed a dog in sixty-one 

 minutes. 



Two cubic centimetres of the poison were taken, 

 and to them were added two cubic centimetres of a 

 solution of potash, containing one gramme of the alkali 

 in six cubic centimetres. Two cubic centimetres of the 

 resulting mixture (containing one cubic centimetre of 

 the fresh poison) were then injected into a dog, but the 

 animal never experienced a symptom of poisoning. 



Two cubic centimetres of the mixed solution of 

 potash and cobra-poison still remained. To these were 

 added two cubic centimetres of the ofiBcinal solution of 

 acetic acid, and one cubic centimetre of the mixed 

 solutions containing one quarter of a cubic centimetre 

 of the original poison was injected into a dog. This 

 ' animal had all the symptoms of cobra-poisoning, and 

 died in one hour and fifty-six minutes. 



Thus we see that cobra-poison mixed with a solution 

 of potash can be injected into the system without pro- 

 ducing any symptom, but that when acetic acid is added 

 to this solution all the powers of the poison are restored. 



