On the effects of sulphate of atropia on the nervous system of frogs / by Sydney Ringer ... and William Murrell.

  • Ringer, Sydney, 1835-1910
Date:
[1876-1877]
Catalogue details

Licence: Public Domain Mark

Credit: On the effects of sulphate of atropia on the nervous system of frogs / by Sydney Ringer ... and William Murrell. Source: Wellcome Collection.

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    the paralysis was incomplete; that in seven of the thirteen in which it had been complete, a partial recovery of reflex and voluntary power had taken place for a day or more before the onset of the tetanus. In eleven of our own twenty-six cases there was incomplete paralysis of reflex action and voluntary power, and in all these cases the onset of tetanus was delayed. In two cases, indeed, both voluntary and reflex power had been completely regained before the tetanus set in. In one case in which there had been complete paralysis, it began to improve five and a half hours before the commencement of tetanus. III. If the poison be prevented from having access to certain limited regions by ligature of the nutrient vessels, the onset of tetanus is still delayed even in these protected parts. Fraser gives an account of four experiments, in which he adopted this mode of procedure. In three he tied the femoral vessels, and in one the abdominal aorta, before poisoning the animal, and yet tetanus did not occur in the protected limbs till twenty- two hours, fifty-one hours, three days, and twenty-two hours respectively. We have tested the action of atropia on ten pithed and pegged frogs, in which, before poisoning, the abdominal aorta had been tied. The following was our mode of procedure:— We first divided the medulla by cutting through the occipito- atlantal membrane, and then passed a pointed wooden peg upwards through the foramen magnum into the skull, so as to destroy the brain. We then placed the animal on its back on the frog-board, and cut through the abdominal wall on one side, usually the left, taking care to avoid the abdominal vein. The intestines were then drawn aside, and the abdominal aorta having been slightly raised, was ligatured just above its bifurca¬ tion. The walls of the abdomen were brought together by sutures, and when the animal had recovered from the shock of the operation we injected our sulphate of atropia solution under the skin of the back. At the conclusion of our experiment we always ascertained by a careful post-mortem examination that the vessels had been securely ligatured. In every instance in which more than two or three drops of blood were lost, the operation was deemed unsatisfactory, and the animal rejected. We give the results of these experiments in the following table :—