MISCELLANY 
The action of Hydrocyanic Acid as a Poison. By Dr. Meyer.— The 
Doctor states as the result of his experiments with this acid on ani- 
mals — 
" 1. That it had a paralyzing action on the peripheric nerves — i. e. 
it suppressed sensation and motion, and occasioned congestion, with 
augmented secretion, which was chiefly observed in the cavity of the 
mouth. 2. He found it to act only when received into the vascular 
system. On mechanically arresting the circulation, the poison did not 
act, although the integrity of the nervous system was preserved. On 
restoring the circulation, the operation of the poison was immediately 
observed. 3. Hydrocyanic acid does not act so rapidly as it was formerly 
believed. Its operation was never instantaneous. 4. Its fatal effect is 
owing to paralysis of the heart induced by the topical action of the blood, 
s^L^teLHiy c dr P. c 2 anicacid I^ 0n thator S an - ^ required about thirty 
lysing effects, and it mattered not whether the poison was applied 
directly to the substance of the heart, or to parts remote from it. In 
Dr. Meyer's opinion, prussic acid may act independently of the brain 
or nerves, or of their intervention. It requires for its operation, absorp- 
tion and diffusion until it reaches the heart. It is owing to this, in his 
opinion, that amphibia are less rapidly killed by this poison than mam- 
malia, the action of the heart in those animals beingless necessary for 
the maintenance of life. Nevertheless, in a certain dose the poison 
may act upon and paralyze the nervous system, producing tetanic 
convulsions, congestion of the veins, and exudations in the serous 
cavities. It is not true, as it is generally believed, that in death from 
prussic acid the blood does not coagulate. Dr. Meyer found that this 
liquid coagulated in the bodies of the animals which were killed in 
his experiments. 77 — British and Foreign Review. 
These observations are to a certain extent confirmed by an experi- 
ment of Liebig. He endeavors to prove that prussic acid does not act 
by sympathy through the nervous system, nor is it absorbed directly 
into the blood ; but that' it can only act through the medium of its 
vapour on the pulmonary mucous membrane. If this statement be 
correct, it may be made to act as a poison, and yet with difficulty be 
discovered after death. — Chemist. 
