214> Mr Murray on Hydrocyanic Acid and Opium, 



Art. VII. — Researches on Hydrocyanic Acid and Opium, in 

 reference to their Counter- Poisons. By John Murray, 

 F. L. S. M. W. S., &c Communicated by the Author. 



In June 1815, a paper of mine was read to the Linnasan So- 

 ciety, developing a simple and apparently decisive method of 

 ascertaining the sedative virtues of vegetable juices and their 

 counter-agents. 



The sciatic nerves of the prepared frog were taken up by a 

 silver probe, and moistened with the tincture, and the result 

 indicated the sedative power or its obverse ; the degree was 

 determined by the specific gravity of the solution employed, 

 and the power measured by the duration of the period requir- 

 ed to produce its maximum effect. 



It would be superfluous now to describe what has already 

 been amply detailed. It was clearly proved from the result, 

 that a suspension of the voltaic excitement, more or less de- 

 cided, was the consequence of certain vegetable juices, and that 

 in such as were operative in this manner, acetic acid was found 

 to be a counter-agent, 



It may be worthy of remark, in this place, that discoveries 

 have since manifested new alkaline bases, characterized by 

 specific characters, in such as having produced a sedative ef- 

 fect, were neutralized by acetic acid, as morphia, atropia, 

 &c. 



The following paper is intended simply to detail the results 

 of some experiments instituted with reference to the discovery 

 of counter-poisons to their agency on the system. Facts are 

 soon stated, and it is not necessary that they be amplified 

 or extended by unnecessary details. The truths gleaned from 

 actual experiment are immutable, while the consequences 

 which may be deduced in support of a theory may soon be 

 overlooked in the progress of intelligence. 



I had always found, that the violent headache which some- 

 times occurred in preparing hydrocyanic or prussic acid, was 

 relieved and removed by ammonia, which induced me to think, 

 that the antidote to that acid and virulent and formidable 

 poison might be found in ammonia. 



