Surra.                                                9

                                                    Injections.

About four hours after the injection on the 16th, the pony
showed symptoms of colic, which increased and the animal
was in great pain and died 16 hours after the injection. The
post-mortem showed acute Nephritis. The kidney was for-
warded to Dr. Hankin, Chemical Examiner and Bacterio-
logist, U. P., who kindly tested for arsenic and atoxyl. In
his reply, he informed us that atoxyl does not give the
ordinary arsenic reactions, until it has been decomposed.
" I found the best methods of doing this to be by treatment
with sulphuric acid and permanganate of potassium, or with
bichromate of potassium in the presence of sulphuric acid
followed by potassium pyrosulphite. A piece of the kidney
treated in the latter way gave reactions for arsenic, but not
strongly. Before such treatment no arsenic reaction could
be obtained. " In a later communication he informs us
that on a quantitative examination of the kidney using the
electrolytic method at least 2.64 milligrammes of atoxyl
were present. In the strong solution of the last injections
the atoxyl was not decomposed in the blood stream and