PREPARATION OF ANTI-RINDERPEST SERUM.   227

precipitated with an equal volume of saturated ammonium
sulphate solution, filtered, and the pseudo-globulin dialysed.
The three fractions thus obtained were tested as follows :—

Bull 281.—Age 1 year. Weight 99lbs.

Inoculated subcutaneously with the albumin fraction on
one side, and 0.5 c.c. virulent rinderpest blood on the other.
Result.—Animal died of rinderpest eight days after inocu-
lation.

Bull 283.—Age 1 year. Weight 138lbs.

Inoculated subcutaneously with the pseudo-globulin frac-
tion on one side, and 0.5 c.c. virulent rinderpest blood on the
other.

Result.—Animal died of rinderpest ten days after inocula-
tion.

Bull 284.—Age 1¼ year. Weight 153lbs.

Inoculated subcutaneously with the euglobulin fraction
on one side, and 0.5 c.c. virulent rinderpest blood on the other.

Result.—Animal lived and was used for serum making.

The previous results are confirmed, viz., the rinderpest
immune bodies are associated with, or similar to, the euglobulins.

Several questions of theoretical interest and practical
importance arise from a consideration of the experimental
results given in the preceding pages. The rinderpest immune
bodies are precipitated on dialysis of the serum which suggests
that they are allied to the euglobulins, and this conclusion is
supported by the result of Experiment 6. Diphtheria and
tetanus anti-toxins are not precipitated by dialysis, and all the
evidence available goes to show that the anti-toxins are allied
to the pseudo-globulins. The difference may be due to the fact
that the rinderpest anti-serum is obtained from bovines and
diphtheria anti-toxin is usually obtained from equines ; that is,
the species of animal used for the production of immune sera
may be a factor in producing the different results. In this con-
nection the results of Pick, Gibson and Ledingham may be re-
ferred to. It would be interesting to determine the distribution
of the diphtheria anti-toxin in the serum of a bull immunised