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An experimental investigation of the effects of hæmosta-
tic and other drugs on the intravascular coagulability of
the blood.

BY

SURGEON-LIEUTENANT LEONARD ROGERS, M.B., B.S.

LOND., F.R.C.S., ENG.

       In December last I read a paper before the Medical Section of the Indian
Medical Congress on " Some Clinical applications of the different methods of in-
fluencing intravascular coagulability," which was based on the work of Dr. Wright
of Netley*and on some experiments I have been doing on the effect of
various drugs on the time of coagulation. As some of the latter had been carried
out under somewhat disadvantageous circumstances whilst on a march, I have
since repeated and considerably extended them, and propose to set forth the
results obtained in the present paper.

       The method adopted is a very simple one. It consists in the determination
of the coagulation-time of the blood both before and after taking a given dose
of a drug by means of Dr. Wright's apparatus,which is figured and de-
scribed in the British Medical Journal, vol. I, page 237, 1894. All the precau-
tions there advised were taken, but, during the latter experiments, the water in
the vessel was slightly above "half blood heat" owing to the impossibility of
getting ice in this station (Doranda). As in the different observations of any
one experiment there was never a difference of more than a fraction of a degree
centigrade, this could not possibly have influenced the results.

       One slight modification of the apparatus was found necessary, namely, the
fitting of a cork to the metal vessel containing the water, and the placing
of it in a horizontal position, in order to prevent the column of blood running
down and drying at the orifice of the tube. Briefly, the principle of the method
is to draw up a drop of blood, obtained by pricking the finger, into a given
length of uniform capillary tubes, and then by blowing down the tubes after
noted intervals of time, say, at half minute intervals, to determine the period at
which coagulation occurs; the shortest time in which the blood is found to be
clotted so that it cannot be blown out of the tube, or, if blown out on to blotting
paper, a clot is found to have been formed in it, is the coagulation-time. As

*British Medical Journal, 1893, Vol. II, pages 57 and 223.

British Medical Journal, 1894, Vol. I, page 237.

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