laborious respiration, and slight convulsive twitches before death.[1] Had these observations been followed up by his successors with a discriminating eye, toxicologists would not have been so much misled as they have been. Orfila, who was the next to examine the subject experimentally, failed to appreciate the phenomena with exactness.[2] He thinks monkshood acts peculiarly upon the brain, causing delirium, and that it is a local irritant, capable of developing more or less intense inflammation. A single experiment made in 1836 convinced me that the former statement is incorrect, and led me to consider that the symptoms depend in a great measure on gradually-increasing paralysis of the muscles, which terminates in immobility of the chest and diaphragm, and consequent asphyxia. Dr. Pereira, in some experiments with an alcoholic extract, published in 1842, took notice of two remarkable phenomena,—an extraordinary diminution of common sensation, evidenced by the animal being insensible to pinching and pricking,—and the total absence of stupor, as shown by the animal following its owner, and recognizing him when called.[3] Similar observations have been made in poisoning with monkshood in man. The ablest investigation yet undertaken into the actions of this substance is contained in the unpublished Inaugural Dissertation of Dr. Fleming.
He found that the most remarkable symptoms are weakness and staggering, gradually increasing paralysis of the voluntary muscles, slowly increasing insensibility of the surface, more or less blindness, great languor of the pulse, and convulsive twitches before death. He farther observed that the pupil becomes much contracted; that the irritability of the voluntary muscles is impaired; that the veins are congested after death, the blood unaltered, and the heart capable of contracting for some time after respiration has ceased. Lastly, he maintains that this poison has not, as is generally thought, any irritant properties, that neither the plant, nor its extract, nor its alkaloid occasions vascularity in any membrane to which it is applied, even, for example, in the lips or tongue while burning and tingling from its topical action; that this peculiar effect is therefore merely a nervous phenomenon; and that he never could observe either the diffuse cellular inflammation described by Orfila to arise from the application of monkshood to a wound, or the inflammatory redness of the alimentary canal noticed by others as one of its effects when swallowed.
Orfila ascertained that monkshood exerts its action through the medium of the blood; for its effects are greater when it is introduced into a wound, than when it is swallowed, and they are still greater when it is injected directly into a vein. It is a poison of very great activity. I have found that thirty grains of an alcoholic extract, the produce of three-quarters of an ounce of fresh leaves, will kill a rabbit in two hours and a quarter, if introduced between
