Reviews and notices of books : Les ptomaïnes, recherches cliniques, physiologiques et médico-légales, par I. Guareschi et A. Mosso.

  • Brunton, Thomas Lauder, Sir, 1844-1916
Date:
1883
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Licence: Public Domain Mark

Credit: Reviews and notices of books : Les ptomaïnes, recherches cliniques, physiologiques et médico-légales, par I. Guareschi et A. Mosso. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    but soon recovered. A rat weighing 76 grammes exhibited no symptoms after the injection of 20 milligrammes of the extract of putrefied fibrine. The difference between the activity of this ptomaine and the ordinary organic alkaloids is very great, so that one may consider it as quite innocent in doses where coniine, nicotine or curara would be promptly lethal. Hydrochlorate of ptomaine obtained from fibrine paralyzes the motor nerves like curara, but probably acts also on the muscles. When the muscle of a frog poisoned by it is irritated at regular intervals, it does not respond to each irritation by a contraction as an unpoisoned muscle would do. The contractions are sometimes high, sometimes low, and sometimes are absent. The excitability of the muscle becomes rapidly exhausted. This condition corresponds exactly to that described by Harnack in poisoning by lead and some other metals. The similarity of the action of ptomaine to curara leads the authors to discuss more particularly the action of curara itself, and they consider that the effect of this poison is not something sui generis but resembles the natural death of the organism. They found that the sciatic of an unpoisoned frog remains for a certain length of time at its normal level, and when it is irritated by opening shocks so feeble as to be hardly felt upon the point of the tongue a regular series of contractions is obtained from the muscle. This is the first stage. During this it is always easy to obtain regular contractions if the stimulus be sufficiently strong, but if the stimuli are very feeble, the contractions may neither be equal nor decrease regularly ;• they may be sometimes higher, sometimes lower, and even be wanting entirely. In the second period, that of diminished excitability, this condi- tion is still more marked, and in order to get regular contractions the stimulus must be increased in power. This second period may be observed in a frog which has been decapitated several hours previously or in one where the nervous excitability has been diminished by the influence of curara, of ptomaines, and of other nerve poisons. Whatever may be the poison employed, the result of poisoning by any drug which lessens the irritability of the nerves is exactly the same as that due to the natural death of the nerve. Under certain conditions Luciani has observed a curious irregularity in the beats of the heart which occur in groups, separated by intervals of quiescence. This takes place under the same conditions and is probably analogous to the irregularity in the contractions of voluntary muscles during the second state of dying, viz. that of decreasing excitability. In the third period the nerve is no longer excitable by strong opening shocks which are isolated and separated by an interval of about a second, while it is still excitable by shocks which are more feeble but frequently repeated, like those of a Du Bois Reymond’s coil. This period is followed by the last, that of the death of the nerve, which completely loses its excitability, whilo the muscle still contracts on direct stimulation. Such is the course of the death of the sciatic nerve in the frog.
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