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C
OP Y.
Hon. P.C.M.0.,
485
I find that Ratin No. 2 is eaten greedily
by house rats - mus rattus and mus decumanus. When eaten it causes death in more than 90 per centum of them within a few
days.
It is well fatal to guinea-pigs. I was not
able to poison rabbits or fowls with it.
I have succeeded in keeping wild rats alive together for many weeks, but I have not succeeded in setting up any really destructive epidemic amongst rats so keptby introduc- -ing other rats poisoned with ratin though these died and were eaten.
Ratin No. 2 so far as I can ascertain owes
its properties to a coccus like organism which is present in it in large quantities and can easily be isolated from it in pure culture.
A large number of experiments have been undertaken in order to prepare cultures from Ratin No. 2 which would be fatal to rats. All the ordinary media and anearotic media and media prepared from rats were used but without any real success; the experiments were however stopped by my all-
-ness.
All the above work was done with Ratin that
was three months old. It is said to keep for six months.
28th. May, 1908.
(Sd.) C. M. Heanley.