The physiological actions of dajaksch, an arrow poison used in Borneo / by Peter M. Braidwood, M.D.

  • Braidwood, Peter Murray.
Date:
1864
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Licence: Public Domain Mark

Credit: The physiological actions of dajaksch, an arrow poison used in Borneo / by Peter M. Braidwood, M.D. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    the cardiac organ is re-excitable, either by mechanical or electrical means after it has once become paralyzed. The heart ceases to contract in systole. The ventricles are observed to be bloodless and pale, whereas both the auricles contain blood—the left auricle and the veins leading to it being distended with dark-coloured blood. Post-mortem Appearances.—These are by no means characteristic. Besides the condition of the heart which has just been mentioned,^ the other organs of the thorax«and abdomen are sometimes partially hyperaemic, but present to the naked eye no other appreciable alteration. The muscles of the extremities contracted readily in the case of frogs when excited directly or through their nerves by a current of electricity; whereas the experiments made on warm- blooded animals gave this curious result, that a strong electrical stream produced dight contractions of the voluntary muscles when they were excited directly, but failed to produce contractions when passed through their nerves. In both classes of animals the muscles retracted on being incised. Electricity, moreover, had no power in renewing the contractions of the heart or of the intestines after death. This diversity on the part of the voluntary muscles of frogs may perhaps be accounted for by the well-known extraordinary con- tractile vivacity of the muscles of these animals, as compared with those of others. The question now suggests itself. How does this poison—dajaksch —produce the paralysis of the heart ? Exclusive of a direct para- lysis of the muscular fibres (which is not likely to be the case, seeing the other muscles of the body remain so long unaifected), this phenomenon may be produced through any one of the three nervous sources which supply the cardiac nerves, viz., through the vagus, through the sympathetic system of nerves, or through the spinal cord. Experimental research has long ago demonstrated tliat the cardiac branches of the vagus have the function of arrest- ing the heart's contractions, while those from the sympathetic are the truly motor nerves, and those from the spinal cord the probable sensory cardiac nerves. The proof necessary, therefore, to deter- mine this point requires to be both negative and positive. Commencing, then, with the former, three sets of experiments were made to exclude the action of this poison through the vagv^: Firstly, The voluntary muscles of a frog having been completely paralyzed by means of woorara, which did not however in the slightest degi'ce affect the contractions of the heart; a dose of dajaksch was next administered to it subcutaneously, and the result was as follows:—The latter poison exhibited its action on the heart in the same time and in the same way as it had done in frogs not previously poisoned with woorara. Secondly, The medulla oblongata of other frogs was broken up with a needle, so as to destroy the origin of the vagus, and this iii itself produced a momentaiy cessation of the cardiac pulsations ; but after these were