Sessional_Paper_1903 — Page 510

HONGKONG.

CULTURE OF THE PLAGUE BACILLUS, ETC.

Laid before the Legislative Council by Command of His Excellency the Governor.

GOVERNMENT BACTERIOLOGIST,

No. 33

I am directed by the Governor to request you to ascertain by experiment how long a culture of the plague bacillus can be maintained in agar-agar, or other suitable media, in a room at the ordinary temperature, such growth not to be exposed to the sunlight.

1903

J. M. A.

27-7-03.

GOVERNMENT PUBLIC MORTUARY, 26th August, 1903.

SIR, Re His Excellency the Governor's query as to the length of life of the B. pestis on agar-agar.

I have the honour to report for His Excellency the Governor's information that the experiment has been started.

I am afraid, however, that a considerable time must elapse before any definite conclusion can be arrived at- -at least several years.

From an examination of the literature on the life of B. pestis hominis in pure culture, one finds that the life of the organism varies within wide limits. SCHULTZ, (Cent. f. Bakt. Bd. xxix, No. 5, 1901), RowI AND and others have found the B. pestis alive and virulent in 4-year old cultures, i.e.. if these be protected from sunlight and kept in a cool place. This long term of life is probably favoured by a shrinking and thickening of bacterial protoplasm. There is no question of spore formation (Archiv. des Sciences Biologiques, 1901).

I have, &c.,

The Honourable J. M. ATKINSON, M.B.,

Principal Civil Medical Officer.

WILLIAM HUNTER.

Minute by His Excellency the Governor.

This answers the question as to possible continuance of virulence of the B. pestis in human beings over a dormant season, but I am afraid that I did not convey my meaning correctly to the P. C. M. O.

What I should like to see subjected to bacteriological examination is, not simply whether the B. pestis will survive, and how long. I want to know, or rather I suggest to Dr. HUNTER that it would be valuable to Science to know, the conduct of a culture over a whole period of a year.

Given a culture in a large quantity of agar-agar, so large a quantity that the bacillus has the most ample opportunity of propagation continuously, will the B. pestis continue to propagate uninterruptedly, the conditions being favourable, or will it, as would a vegetable seed, lie dormant for a time and then at the recurring period of the year again actively propagate? (2) It will be equally valuable to know, whether during the dormant time-if there be, as I assume, a dormant time -the B. pestis is virulent. All this would be determined in one year.

Page 510Page 511