An experimental inquiry into the physiological action, the poisonous properties, and the therapeutic effects of the hydrocyanic acid / by Henry Lonsdale.

  • Lonsdale, Henry, 1816-1876.
Date:
[1839]
Catalogue details

Licence: Public Domain Mark

Credit: An experimental inquiry into the physiological action, the poisonous properties, and the therapeutic effects of the hydrocyanic acid / by Henry Lonsdale. Source: Wellcome Collection.

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    ments made with the strong acid ? The experiments exceed in number, so far as I am aware, those performed by any single ex¬ perimentalist in this country, and are, I hope, amply sufficient to enable us to arrive at some satisfactory conclusions, as to the ac¬ tion of this powerful substance on the animal economy. The ac¬ cession of vertigo and convulsive action of the extremities, while the movements of the heart continue with a greater or less degree of regularity, distinctly show that the brain and spinal cord are directly affected. The diluted acid, as has already been shown, has an influence on the heart's action ; but that exerted by the strong acid, as might be anticipated, is more marked and power¬ ful. It must be distinctly understood, that when it is stated that the heart is affected, it is at the same time maintained, that the more direct action of the acid is on the sensorial functions. That the heart should be influenced, is not surprising when we remem¬ ber its close connection with the central organs of the nervous sys¬ tem, and the facility with which its functions are disturbed by causes acting directly on the brain, as exemplified by the pheno¬ mena attending concussion. We do not expect any necroscopic appearances to prove a lo¬ cal influence of the acid on the brain, an organ which can only be affected from nervous or vascular connection with the part to which the poison is applied. It may also be remarked that, in some cases of simple apoplexy and other diseases terminating suddenly, in certain forms of jaundice, and ischuria renalis, where the bile and urea are not eliminated at their respective organs, but remain in, and are carried along with, the blood to the brain, and there act as poisons, exciting convulsions and coma, symptoms similar to those which follow the administration of the hydrocyanic acid, we find nothing on dissection indicating any disease of the cerebro¬ spinal axis. Dr Christison states, with regard to two experiments which he performed, where the acid was given by the mouth in large doses, and destroyed the contractility of the heart, at the same moment that he believes idiosyncrasy may affect the results. As a far¬ ther explanation of these cases, I am inclined to add, what ap¬ pears extremely probable, that some of the vapour of the poison wras drawn into the lungs during a sudden inspiration of the ani¬ mal. From a careful review of the preceding facts, I am constrain¬ ed to believe, that the immediate effects of the anhydrous acid are exerted on the brain and spinal cord, and that it also indi¬ rectly enfeebles, to a greater or less extent, the contractility of the heart. Cases may occasionally be met with (but I feel as¬ sured that they will be few in number) which may lead an expe¬ rimenter to doubt the accuracy of my conclusions ; but I think.