10
watering, or the drainage of their stables which would account for the outbreak.
All these conditions, in so far as they affect the horses' health, have been, to the
best of our belief, precisely the same these last four months, as during the many
past years when " Surra " was unknown to us. We, therefore, seem directed to
seek in some special climatic and atmospheric conditions for the explanation of
the outbreak. October and November last were notoriously exceptionally
unhealthy months in Bombay. Malarial and typhoid fevers were prevalent, and
many cases ended fatally. Unusually unhealthy months for human beings, they
would appear to have been unusually unhealthy for horses also. The outbreak
of " Surra " fever was not confined to the Company's stables. Several horses
attacked with it were sent to the Government Veterinary Hospital, and others
to the private veterinary establishments in the city. Probably, a far larger
number died in their owners' stables. Amongst the cases observed we have
not heard of a single recovery. Taking all the above facts into consideration,
the opinion we have been led to form is that there was some specially
unhealthy influence in the atmospheric conditions this last autumn, which pre-
disposed horses to this particular blood-poisoning fever, and that the specific
cause which developed the disease into activity in the' horses attacked with it,
was getting chilled from exposure to the cold northerly winds, which during the
latter half of November and. the month of December blew in the evening and at
night. This is the conclusion to which we have been led as the result of our
own experience of the disease. In support of this opinion we have the following
facts :—(1) That the horses attacked were found to have been especially exposed
to cold night winds by their position in the stables, or nature of their work. At
Parel stables, where the majority of cases occurred, alterations in the buildings
were in progress. The south wall of the stable had been taken down in order
to increase the number of stalls in that direction. This open condition of the
premises on that side, while it did not expose the horses to any unwholesome
wind (the south wind only blowing in the monsoon time, and being a warm one)
tended, no doubt, to increase the draught through the stables from the north, and
to lower their temperature at night. (2) That since the time when we intro-
duced measures for protecting the stables from the northerly winds ( a period of
five weeks), no fresh case of " Surra " has occurred. The last case at Parel
stables appeared on the 29th December. It was on the 30th of that month
that we completed the arrangements for excluding cold winds. (3) That the
Parel stables, where nearly three-fourths of the cases occurred, were, until
recently, in consequence of their system of construction, more open and consi-
derably colder than the stables at Colába. (4) That there is nothing ascer-
tainable in the feeding or watering of the horses, differing from the feeding or
watering during previous years when Surra was unknown to us, or which can, in
our opinion, in any way account for the outbreak.
In connection with the exposure of the horses to cold winds and our opinion
that the chill to the system therefrom resulting was the immediate factor pro-
ducing actively in the disease, we may mention that out of 8 horses working as
" helping " horses on the Byculla bridge, no less than 3 were attacked with
" Surra, " and of these two were attacked upon the same day. Compared with
the work most of our horses do, the work of these particular horses was light,.
and they were in specially good condition and of exceptionally fine physique.
These horses are attached as additional horses to help in pulling cars up the
inclines on the bridge. After pulling up a car they return to the little waiting-
sheds provided for them at either end of the bridge, and stand usually about
five minutes, until another car approaches. On examining these sheds, we found
them a good deal exposed to the north wind. We have now protected them ;.
but it is easy to understand how in the early morning, or between 7 P.M. and
11 P.M. at night, these horses after getting warm at their work would be special-
ly liable to chill when standing waiting in sheds, until recently not very well
protected from cold winds.
In the plains of America it has been noticed that in certain thinly populated
districts where fever was prevalent, the introduction of railway tracks and the
passage of trains has modified the sanitary conditions. The theory in expla-
nation of this fact is that the displacement of air caused by the rapid passage of
the train creates a vacuum and consequent draught, and that a rush of fresh air