BIOLOGICAL AND MICROSCOPICAL DEPARTMENT. f> 



3d. That the Janitor be requested to place the microscopes of the Section 

 on the table at every meeting. 



4th. That arrangements be made with the new Medical Journal to publish a 

 synopsis of the proceedings, and, if possible, to announce the subject for dis- 

 cussion before the meetings. 



The following paper was ordered to be published : 



Is Atropia an antidote to Hydrocyanic Acid ! 

 BY DR. W. W\ KEEN. 



Having been recently called upon, as a member of a committee of the 

 Pathological Society, to investigate the blood of Geo. S. Twitchell. Jr. the 

 murderer (who poisoued himself by prussic acid), my attention was called to 

 the lately asserted antidotal powers of atropia, and I made a number of ex- 

 periments on the subject, the result of which 1 now report to the Department. 



In the Glasgow Med. Jour., Nov., 1808, p. 70 et seq., will be found an ex- 

 tended analysis of Preyer's recent work on prussic acid (Die Blausaiire, Bonn 

 1808), which I must quote as authority, as I had not access to the original 

 work. The questions as to action of the poison on the spectrum analysis of the 

 blood, ou its coagulation, on the heart, &c, are foreign to my present purpose 

 and will be found discussed both in the paper just alluded to and in our re- 

 port to the Pathological Society. (Amer. Jour. Med. Sci. vol. 58, p. 432. i 



Preyer's conclusions, from numerous experiments, are that HCy kills by 

 suffocation induced by three means : 



1, it stimulates or tetanizes the pulmonary branches of the vagus, so that 

 the respiration ceases. 



2, it stimulates or tetanizes the cardiac branches of the vagus (and also the 

 sympathetic ganglia of the heart in some cases), and thus arrests the circula- 

 tion. 



3, it acts on the respiratory nervous centre, so that the breathing on beino- 

 re-established is retarded more and more, till death follows. 



Atropia, he states, has precisely an antagonistic action, and therefore 

 should be and is an antidote. That atropia does have such an aciion as he 

 has asserted on the circulation, is the conclusion to which Drs. Mitchell, 

 Morehouse and myself came in studying the antagonism of opium and bella- 

 donna, and published in the Amer. Jour. Med. Sci., July, 1865; but that it 

 affects the respiration is contrary to our experiments at that time, and that it 

 aets as an antidote to prussic acid my present experiments, so far as they go, 

 certainly disprove. 



Preyer states that if the 0-015 of a grain i. e., one millegramme of sulphate 

 of atropia be injected under the skin of a rabbit, a lethal dose of HCy may be 

 given without producing death ; or if the HCy be first administered, tint then 

 the atropia will arrest its poisonous action if it is given quickly enough. 



Exp. I. May 12, 1869. Injected 0-017 gr. of sulph. atropia under the skin of 

 the back of a rabbit, followed in half a minute by 3 fl1 of officinal dilute hy- 

 drocyanic acid. 



In U minutes after the last injection he fell over convulsed; opisthotonos. 



In 2| minutes pupils began to contract. 



In bk minutes respiration had ceased ; heart still beating. 



In 6J- minutes, dead. 



On the post mortem examination, made immediately, the heart was found to 

 present the slight rythmical twitching usually noticed in the right auricle 

 after poisoning by HCy, but here observed in the walls of all the cavities save 

 the right ventricle. 



Exp. II. Injected as before under the skin of a rabbit gr. 0-010 atrop. sulph., 

 followed in half a minute by 2 TT1 HCy. 



In 2J minutes respiration arrested. 



