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16. The first essays made by Dr. Galeotti on rats gave very satisfactory results,
and these result will be communicated to the Plague Commission together with those
of the following experiments by Dr. Galeotti himself.
17. In accordance with my personal experience on the preparation of curative
serum in general and specially in regard to the preparation of the antiplague serum,
I must say that not all the horses are able to give a serum imbued with sufficient
curative properties, and that some horses are able to give a good serum only after a
long process of repeated inoculations.
18. I believe that the strength of the serum prepared, following my method, is
due to the presence in the blood of substances elaborated by the cells of the organism
of the horses, during the general reactions, which follows every inoculation.
19. When the activity of the serum is in proportion to the number and strength
of these reactions, the horses, able to give strong reactions, will furnish surely an active
serum.
20. On the contrary, the horses in bad condition of nutrition and in which the
material exchange is abnormal, show, after the inoculations, phenomena of im-
proverishment and topor, and are not able to give a sufficiently strong serum.
21. For this reason, it is necessary to keep the horses quiet for some time after
the first blood letting and before making new inoculations.
22. I have requested Dr. Galeotti to give to the Plague Commission the most
detailed information about the experiments which will be done on plague patients
with the serum of the horses which are now under treatment, and also, in regard
to the researches designed to determine on rats, with the greatest exactness possible,
the strength of the serum of every treated horse.
23. Being requested by the Municipal Commissioner to express my opinion
on the importance of rats in the diffusion of the plague, I offer the following :—
1st. I have performed experiments on hundreds of rats of different races, and
living in the most different conditions, and I have found that almost all are able to get
plague.
2nd. Keeping in a cage several infected and non-infected rats 3 all die in a
short time, and in their bodies plague microbes are always to be found.
3rd. Mixing a virulent plague culture with the food given to some rats, all
these generally die from plague, and it is quite common to find the bacilli in their
foeces.
4th. Generally in the infected rats the microbes enter the blood, and with great
facility they pass into the urine ; thus this urine becomes a very infectant liquid.
5th. In 1897, I had occasion to examine at Poona some dead rats found in a
granary, and in these I found plenty of microbes. I investigated also the corn of this
granary, but I did not discover any plague microbes in it. Nevertheless, I know
that 2 cooks who ate of this corn died from plague a few days after.
6th. I believe that the rats represent one of the most important means of
diffusion of the disease, because they are able to carry everywhere virulent microbes.
7th. The destruction of the rats is one of the most important measures to be
taken against the plague. For this purpose poisons can be very useful, and specially
would it be useful to provoke amongst the rats another epidemic, with a microbe not
virulent to man. For this purpose, I believe that the Laser's microbe would be