25

which there was then added a different amount of the venom of Bungarus fasci-
atus. The strengths of the venom solutions used were 0.1 per cent. and 1 per
cent. From one to two hours afterwards there was added to each tube a quantity
of calcium chloride solution which clotted the control in less than 15 minutes.

    The following were the results obtained :—

(a) Donkey plasma (1 per cent. citrate).

(b) Horse plasma (1 per cent. citrate).

SERIES No. V.—Experiments to demonstrate the result of the hœmolytic action
of the venom of Bungarus fasciatus, unheated and heated, in vitro on the
blood of rabbits.

    A sample of the venom of Bungarus fasciatus was dissolved in sterile salt
solution (0.75 per cent.). The strength of this solution was 0.2 per cent. A
portion of this solution was heated in a water bath at 75° C. for half an hour and
then filtered to remove the coagulated proteids.

    An estimation of the hæmolytic power of the original unheated venom and
of the heated solution was made. Each tube in the series contained 0.5 c.c. of
venom solution, which was half the strength of the solution in the tube next
above it in the series.

    The dilutions were made with salt solution (0.75 per cent.). To each tube
was then added 0.005 c.c. of fresh rabbit's blood drawn from the artery of the ear.
The preparations were kept at laboratory temperature (about 25° C.). The
observations were recorded 20 hours after the preparations were made.

E