Sessional_Paper_1911 — Page 177

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INTRODUCTION.

An investigation of Pokfulum Water Supply, as to whether there was evidence of contamination or not, was ordered by His Excellency the Officer Administering the Government Sir Henry May, K.C.M.G., in a minute dated October 6th, 1910, (Č.S.O. 2533/1909). This investigation has occupied practically twelve months.

As the lines along which the investigation was to take place were left undefined, it appeared to me that the most profitable line of investigation to take would be a research into the presence and characters of the Lactose fermenting organisms in the water- leaving such subsidiary indicators as Streptococci and Bacillus Enteritidis to be gone into only if time permitted.

As the work progressed, it soon became evident that if the Lactose fermenting Bacilli were to be worked out with any thoroughness, other side-issues must be left alone on account of want of time. This course was adopted and the following report consists essentially of an investigation of the Lactose Fermenting Bacilli.

No attempt has been made to isolate and classify the usual array of harmless water organisms. This has been done repeatedly elsewhere and the amount of information as to whether the water is polluted or not which can be derived from it is negligible.

Briefly the method pursued in this research was that if an organism was isolated which did not ferment Lactose, it was discarded. This naturally puts Pathogenic or- ganisms such as Typhoid and Cholera out of the scope of the investigation, but, as will be pointed out below, it should be a well known fact that the chances of isolating these organisms, even if present, are very small.

The statement often seen in Water Reports-"No pathogenic organisms present", is of no value whatever unless details of the amount of work done to isolate the organisms are also given.

There are no animals in the area except a few deer, some dogs and birds; it was therefore not considered necessary to investigate the Lactose Fermenting Bacilli of animals. An investigation of the Lactose Fermenting Bacilli of healthy Chinese has however been made and the results obtained have been compared with those of Mac- Conkey (1905) in England, Major Clemesha (1909) in Madras and Castellani (1910) in Colombo.

The methods used and the results obtained with the Lactose fermenting organisms have been recorded briefly as exactly as possible in order that any one may be able to draw his own conclusions on such a disputed group as the Coli Group. As the Bacteriological results alone are not sufficient grounds for judging a water, Mr. A. H. Hollingsworth, Executive Engineer in charge of the Water Branch of the Public Works Department, has been good enough to supply a short note or the Water Works them- selves, and I have added some topographical notes on the Catchment area from personal inspections.

In an investigation of this kind-involving so many laborious details-it would have been impossible to get over the work done without the very capable assistance of Mr. Chan Tsun-kon, L.M. & S., Hongkong, the Bacteriological Assistant. He has taken a most energetic part in the work and the whole staff of the Institute has worked exceedingly well.

A list of the original papers made use of in this investigation is given at the end of the Report; as some excuse for the incompleteness of this list the isolated position of Hongkong must be taken into account.

GOVERNMENT BACTERIOLOGICAL INSTITUTE,

Hongkong, 1st October, 1911.

HAROLD MACFARLANE,

Government Bacteriologist.