7

As noted in last year's report, there seems to be little relation between the death-
rate from small-pox in 1894 and the proportion of successful vaccinations done during
the last seven years. The relation would be doubtless much more obvious if a larger
proportion of the population were protected.

Animal lymph depôt at Shillong.

27. The Annual Report of the Animal Lymph Depôt at Shillong, by Surgeon-
Captain Carroll, is given as Appendix A to this report.
The expenditure on the depôt, Rs. 6,815-2, was Rs.
1,308-8-8 in excess of the expenditure incurred last year. The increase in the expendi-
ture was principally due to the larger number of calves inoculated and to the increased
mortality among the calves, cattle-disease, similar to the epidemic of 1890-91, having
been very prevalent. Lymph was not sent from the depôt till the end of October, and
Civil Surgeons agree in reporting that the first supplies were of excellent quality. The
quality of lymph supplied remained very fairly good till about the middle of December,
when it began to deteriorate, and that supplied during January and the first week of
February to most of the districts in the plains proved almost inert. The lymph
supplied during the remainder of February and the whole of March was, on the whole,
good. On finding out that lymph of bad quality was being furnished by the Shillong
depôt, I telegraphed to the Superintendent of the Darjeeling depôt, requesting him to be
good enough to send supplies of bovine lymph to the Civil Surgeons of this province and
to the depôt at Shillong. The deterioration in the quality of the lymph was doubtless
due to the Civil Surgeon of Shillong, in his endeavour to supply as much lymph as
possible, sending out lymph taken from calves inoculated with lymph which had passed
directly through four generations of calves without having been strengthened by
humanised lymph. On finding that the Civil Surgeon of Shillong was supplying lymph
of the fifth generation, I directed him not to send out lymph in future which had
passed more than three generations through calves without having been humanised.
The lymph sent out in January was not altogether inert, as the Civil Surgeon of
Manipur reports that it was excellent. The results obtained in the Nága Hills during
that month were also very good, and a portion of that supplied to Lakhimpur was
efficient. In consequence of its not having been sufficiently strengthened by the
addition of human lymph, it was not, however, sufficiently strong to resist the effects
of the climate in the Surma Valley and the lower portions of the Assam Valley. By
arranging to have a sufficient supply of active human lymph, and by not sending out any
lymph beyond the third generation, I believe that the Civil Surgeon will be able to
supply efficient lymph next season from the Shillong depô .

                                                            I have the honour to be,

                                                                        Sir,

                                                          Your most obedient Servant,

                                                     A. STEPHEN, M.B., Surgeon Colonel,

                            Offg. Principal Medical Officer and Sanitary Commissioner, Assam.