173 REPORT — 1866. 



Beport on the Physiological Action of certain Compounds of Amyl 

 and Ethyl. By Benjamin W. Richardson, M.A., M.D., F.R.S. 



In two previous Eeports to the Association, I dwelt especially on the action 

 of certain of the compounds of amyl. The first Report dealt exclusively 

 with the substance known as the nitrite of amyl. The second lleport had 

 further reference to the same body, and also to amylene, amylic alcohol, and 

 the acetate and iodide of amyl. In some degree these Reports were com- 

 plete as far as they went ; that is to say, the facts presented Avere sufficient 

 to demonstrate what visible physical influences -were exerted on dead and on 

 living matter by these representatives of the amyl scries ; and as I care- 

 fully separated the facts from the speculations that were fairly to be founded 

 on them, the Association expressed its satisfaction by requesting me to con- 

 tinue researches in the same direction but with a wider object. I was de- 

 sired in the next Report to repeat what might require repetition, but specially 

 to pay attention to the etlii/l-comjyounds, with a view to determine, if that 

 were possible, whether there was any analogy in physiological action between 

 the analogous compounds of the two series. 



SUMMARY OF PAST RESEARCHES. 



Before I enter on new ground, it will be advisable for me to recall the 

 main facts described in previous years and bearing on the amyl series. 



1. It was shown that the nitrite of amyl when inhaled was the most poAV- 

 erful excitant of the circulation at the time known. It was demonstrated 

 that during such inhalation the action of the heart was doubled in rapidity 

 in thirty seconds, in men and warm-blooded animals : further, it was proved 

 that this intense action was immediately followed by deep suffusion of the 

 skin, by Lreathlessness like that produced by runnhig, by a peculiar sensation 

 of fulness and throbbing in the head, and ultimately by failure of muscular 

 power of the extremest kind. It was also proved that there was no destruc- 

 tion of the nervous sensibility, that in animals there was an obvious expres- 

 sion of sensibility up to the moment of death. Lastly, it was shown that in 

 cold-blooded animals, such as frogs, the nitrite of amyl suspended animation 

 for hours, and even days, — and that, in young warm-blooded animals, after 

 exposure to it until they seemed to be dead, the action of the heart continued 

 for so long a period as eigliteen hours. 



2. In respect to amylene, it was shown that the vapour of it was antiseptic, 

 even when freely admixed with air ; physiologically tested on living animals, it 

 is found to be capable of administration by being inhaled. It does not provoke 

 local irritation, but it rapidly produces collapse and total insensibihty to 

 pain. At the same time it seems to interfere less with consciousness than 

 other narcotic vapours. This fact is of peculiar interest, because the appa- 

 rent consciousness exhibited by the subject is not shared in by himself, it 

 is an objective, not a subjective phenomenon. The person under the influ- 

 ence of the vapour may perform acts which have all the semblance of conscious 

 acts ; but when he recovers he has no recollection of anything that has oc- 

 curred. The state thus induced is very much like the phenomenon of som- 

 nambulism ; and I ventured to suggest that in this experiment we had a 

 key to tlie cause of the disease somnambulism, viz. that there was possibly 

 formed in the body of the somnambulist, by a faulty digestion, a substance 

 of similar action to an aniyl-compound. Am3'lene I showed was a good 

 anaesthetic, and many surgical operations have been performed under its in- 



