69
years ? It would be impracticable to recommend all the irrigation channels to be
made " pakka," and kept clean; yet if my opinion, as expressed above, is correct,
nothing short of that would do. But the water could be corrected by boiling it every
day before the horses drink it, which would be a very expensive process in a district
where fuel is so scarce. I do not know what else to recommend, unless good water
can be got at reasonable cost by Artesian wells from below the salt strata, or pipes be
laid down to draw water direct to the posts from the rivers above where they are
broken up to supply the irrigation channels. The pipes need not be large. It is
simply a matter of expenditure with regard to the average annual loss of horses from
this disease, and the correctness of my opinion as to the causes of it, which I here
submit for His Honor's consideration. I wish much that I were able to advise upon
this subject with less hesitation. There can be no doubt that the water is very bad,
but whether it has any direct relation to surra as a remote cause has not been proved,
and perhaps cannot be proved without an expensive experiment as above recommended.
32. Cure.—I am very sorry to add that I have less hopes of finding a cure
for the disease than I have of finding a prevention. The experiments I have made
with carbolic acid do not promise success. Besides case 4, recorded in appendix I),
the following horses were selected for treatment exactly in the same manner, namely,
4th Punjab Cavalry, Nos. 1169, 939, and 1235. I selected them because, though
they suffered undoubtedly from surra, having the blood parasite, &c., they were
mild cases, had been about three weeks on the sick list; there had been no dropsical
swellings; they fed well, and did not look ill any way to an ordinary or casual
observer ; they seemed in good spirits, and were in good condition. They had been
placed upon the sick list only because the mucous membranes were yellow with
petechia, which the salutri had discovered in the course of his inspections. No
medicine had hitherto been given, for I had requested, before I went to Dera Ismail
Khan, that the cases submitted to me should not be complicated by the action of
medicine, as I wished to study the disease in its natural course. I tried carbolic acid
in these cases because it has been recommended for parasitic blood diseases, though I
have no confidence whatever in it for such cases. I think the blood impregnated
enough with it to kill the parasites and their germs or ova would be fatal to the patient
also. The few cases recorded of recovery after its use in anthrax have not I believe
been assisted by it. However, I thought it was my duty to give it a trial in this
disease as I could not suggest anything better. A memo from the officer commanding,
dated the 3rd instant, reports as follows:—Out of the four horses treated with
carbolic acid and glycerine two have died: No. 337 (case 4, appendix D) died on
29th October, No. 1669 died 31st October. The two horses remaining under treat-
ment are daily becoming thinner and weaker, and no benefit appears to be derived.
33. The parasite.—I made the following notes when observing it at Dera Ismail
Khan with Swift's best lenses, one-fifth, one-eighth, and one-twelfth (immersion). The
one-fifth is the best lense to see its movements and operations ; the higher powers
should not be used until it becomes quiet. In order to see all its operations, it is
better to examine it in the serum after the blood has coagulated, or in defibrinated
blood, and not to put too little on the slide,* or else the blood dries up quickly
and the parasite will wriggle while he can to get out, but he will not fasten to the
corpuscles as I shall presently describe. Put a fair drop of fresh serum on the slide,
lay the thin cover on, press it moderately so as to squeeze some of the blood from
under the cover all round, retain the pressure a short time until what has been so
pressed out coagulates or dries up and forms a good temporary cement which will keep
the serum within from drying. The movements of the parasite can then be watched
for many hours. If it be required to see it at rest, then a very thin layer of blood
should be put on the slide and allowed to thicken a little before covering it. The
shape of the parasite, however, will be found to differ at rest, if the blood thickens soon,
from what it is if the serum be kept fluid long, and the parasite die slowly. In the latter
case the body spreads out and flattens ; in the former it remains contracted.
34. When I first saw it I thought for a moment it was some form of spirillum, but
the next instant convinced me it was not.
* This observation is meant specially for observers in such a remarkably dry atmosphere as that of Dera Ismail Khan.
The parasite soon ceases its peculiar operations upon the red corpuscles when the serum thickens by evaporation.