1S6 Mr Murray on Hydrocyanic Acid and Opiimi^ 
Was convuLsed. Strong ammonia was dropt into the animars 
mouth, and it was repeatedly moistened with a sponge dipped into 
ammonia. It almost instantly revived, and even' licked repe'ated- 
ly the finger which sometimes applied the ammonia, apparently 
quite sensible of the instant and continued relief it afforded. 
The animal effectually recovered. Its lips were excoriated by 
the ammonia. 
Conscious of the complete antidote to this formidable poison 
found in ammonia, I took a quantity of hydrocyanic acid, suffi- 
cient to produce violent headach, stupefaction, &c., but diluted 
ammonia afforded me instant relief. I occasionally applied it 
to the olfactory organs, and bathed the forehead. 
Since hydrocyanic acid has been introduced into our pharrna- 
copoeia, and employed in phthisis pulmonalis^ and accidental poi- 
soning may be anticipated, it is of much moment to know an ef- 
fectual barrier to its virulence ; and such is my complete convic- 
tion of the antidote, that I would feel no hesitation Adiatever in 
taking a quantity sufficient to prove fatal, provided there stood 
by a skilful hand to administer the remedy. 
It is admitted that morphia is the active principle in opium. 
Morphia dissolved in alcohol, in which, how^ever, it is sparingly 
soluble, produced, on the sciatic nerves of a prepared frog, ef- 
fects analogous to those of the tincture of opium. Acetic acid 
restored the voltaic excitability. 
The sciatic nerves were moistened with superacetate of morphia, 
but the excitement was the same as if none had been applied. 
A frog’s head and abdominal viscera were steeped in superace- 
tate of morphia, but the voltaic action remained unchanged. 
Half a drachm of superacetate of morphia was given to a 
young rabbit, but no apparent derangement of its healthy func- 
tions took place : it rather seemed to act as a stimulus to appetite. 
These experiments pointed out acetic acid as the counter-poi- 
son to opium, and from its volatile properties, and other charac- 
ters, in which it differs almost essentially from acetous acid, ha- 
ving no affinity with it except in an acid character, and having 
much of the features of an ether, I am of opinion acetic acid may 
prove serviceable where acetous acid would not prove effectual. 
Two and a half drachms of tincture of opium were given to a 
rabbit. In a short time the eye became more opake, the pupil 
