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.

    14/32 (page 14)
    of the hydrocyanic acid, it is impossible to lay down general con¬ clusions on the first of these questions. From a carefid calcula¬ tion of the ages, weight, &c. of several animals, and the doses ad¬ ministered to them as compared with man, I think it probable that a drachm of Scheele’s acid would affect an ordinary adult within the minute, and adose exceeding this, suppose threeorfour drachms, would exert its influence within ten or fifteen seconds. When the acid is stronger, and the quantity larger, we are pretty certain of its immediate action and consequent annihilation of the sen¬ sorial functions. 2. As to the time at which the acid proves fatal ? There are records of cases of the human species poisoned by the prussic acid where death occurred as early as the second minute, and as late as the forty-fifth minute. Should proper measures be adopted for the recovery of those poisoned, it seems probable that those who survive the fifteenth minute may recover. Most physicians will agree with me in thinking that the Parisian epileptics, if pro¬ perly attended to, would have lived; and it deserves remark, that a smaller dose than that which they took is not likely to prove fatal. The dose amounted to 20 drops of the medicinal acid, which, allowing the acid to be of3J per cent, strength, would con¬ tain about two-thirds of a grain of pure acid.* 3. What symptoms are characteristic ? The loss of conscious¬ ness and voluntary motion, the slow, deep, and heaving respira- torv movements, whilst the circulation eraduallv becomes en- 7 o J feebled, the fixed and insensible iris, in short, all the characteris¬ tics of apoplexy, were observed in the lower animals, and the same were observed in the physician at Rennes. It is far from im¬ probable that a person may have a dose of prussic acid given him, so proportioned as to induce a simulated apoplexy, which, if the medical man was unaware of the cause, might be mistaken for the real disease. For it must be remembered that when doses not rapidly fatal are administered, the convulsions and tetanic spasms soon subside, and the animal lies in the apoplectic state for some time. So far then there is some difficulty in theway,andaknowledge of the general symptoms would be inadequate. But there is one circumstance which has received no attention from medico-legal writers, and that is the exhalation by the breath of the acid vapour. This has been observed in the human species, and numerous ani¬ mals experimented upon by me, as already mentioned, and cer¬ tainly would be sufficiently characteristic of the poison having been taken. After a due attention to the symptoms, and the time and mode * Dr Geoghegan (Dublin Journal of Med. Science, Vol. viii. p. 309,) relates a case of poisoning, where about the same dose was taken, yet, by the application of reme¬ dial agents, the person recovered.