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not by impressed coolies: 5th, that a house infected, should not be re-occupied for 10 days: 6th, that a patient should not be sent to a plague hospital till his disease has been diagnosed by a qualified medical man and that, when sent, he should be taken as direct as is possible to that hospital; 7th as people from Canton who become panic-stricken probably visit this place carrying infection with them, it seems desirable that the fresh arrivals be kept uuder surveillance.
(Sd.)
J. D. DALY, M.B..
Major, I. M. S.
Camp, KOWLOON,
5th June, 1901.
To the Principal Medical Officer,
SIR.
China and Hongkong,
In continuation of my report on the sanitation of the village of Hunghom, I have the honour to now submit the following report on the drainage system of that village, as ou the previous occasion. Í had not an opportunity to fully examine it. I inspected yesterday, accompanied by a representative of the Public Works Department.
The house drains are intended for slops, washing water and waste house water only. The stops, &c., run from a sloping floor into a cemented channel along the side of the cook rooms, discharging through the wall of the house over an open hopper head of a down-pipe. There is no direct connec- tion. This down-pipe discharges into a gutter at the roadside being likewise disconnected. The arrangement is so far good. These gutters in turn discharge into the sewers and are trapped at entrance. The smaller sewers discharge into the main sewers which have man-holes for cleaning purposes, traps being formed in connection with the man-holes. Those sewers are intended to carry off the house drainage and in part the rain water. When practicable the rain flood water is carried off through open nullahs. The main sewer is provided with overflow comection with nullahs as a provision for floods. The main sewer finally runs out into the sea and discharges in the harbour. There is only one ventilating shaft in connection with the whole system. The system is defective in the following respects:-That 1st, owing to the want of ventilation, the varions traps must, during heavy rains, become unsealed by syphon action and sewer gases consequently escape freely into the streets through the man-holes and gullies; 2nd, that as the main sewer opens directly into the sea, there must result, during the time of high tide, what amounts practically to a cessation of the working of the whole drainage system as, owing to the low level of the site of the village, the head or pressure from behind can effect but little in the discharge of the sewer. During this time there must e an accumulation of drainage water, as a considerable portion of the main sewer is then filled by the side. This accumulation must displace the sewer gases and force them out through the man-holes and gullies into the streets, as the quantity of water in the traps cannot be sufficient to absorb all the sewer gases under such conditions. A third defect in the system is the want of any flushing arrangements. The rainfall suffices during part of the year, but during the dry season sewer gases must be largely generated from decomposition of filth of various kinds which sticks to the walls of the drain. This condition will naturally become worse as drains become older.
I should recommend that the entire system be ventilated, obviating the present escape of sewer gases during high tide and heavy rain; and 2nd, that arrangements be made for flushing during dry weather; and 3rd, that some arrangements be made to allow the continuance of the discharge from the sewers during the time of high tide.
I have the honour to be,
Sir,
Your most obedient Servant,
(Sd).
J. D. DALY, M.B.. Major, I. M. S.