838
THE HONGKONG GOVERNMENT GAZETTE, 26TH SEPTEMBER, 1891-
This analysis conclusively proves what I have advanced in this report to the origin of the solids in the water. It should be borne in mind that the quantities of several of the constituents vary according to the time of the year. Owing to the proximity of the reservoir to the sea, strong gules carry the spray inland, which fact alone accounts for a variation in the sodium chloride figure. I have frequently detected the presence of salt in rain, and have estimated the amount. In June last in rain collected near the hospital, in a special apparatus, the quantity of chlorine varied from 77 to 1.1 grains per gallon, which was doubtless due to variations in the force of the wind.
15. CONCLUSIONS :-There remains now only to suggest a possible remedy for the whitish appear- ance of the water. This is a matter of considerable difficulty, and as stated in the covering letter, it has been arranged with the Resident Engineer to make a joint report as directed. I deem it wise however to make some preliminary suggestions in the hope that they may be found of some service.
16. It has been found that the power of water to hold clay in suspension is increased by the presence of small quantities of Alkali, Alkaline Carbonates, or Earthy Carbonates, while it is diminished by addition of small quantities of Sulphuric Acid, Alum, or Sodium Chloride.
17. It seems self-evident that one of the most important things is to do away with the necessity of filtering extremely turbid water by a more extended application of the principle in use at Pokfulam and described in paragraph 4. Secondly, that the ground in the collecting areas should be disturbed as little as possible, and if landslips of any magnitude occur, the freshly exposed surfaces should be protected by turfing or otherwise. It does not seem that much else can be done in the way of prevention. The formation of Kaolin in the water in the first instance cannot be stopped, while as for removing it when formed, by simple filtration, the experience of the Worcester authorities and the Engineer here, is that it cannot be accomplished. Chemical treatment previous to filtration will have to be resorted to, if it is considered essential, to have a perfectly bright water at all seasons of the year. I have made numerous experiments, but I do not think anything would answer on a large scale excepting treatment with an Alum. Several substances if added to turbid water have the property of precipitating the suspended matter, but all are more objectionable than Potash Alum. The Alum treatment has already been the subject of a memoir by Mr. CROw, and will be fully dealt with in a future communication. It should be borne in mind that for a great part of the year, the unfiltered water is comparatively clear and does not require chemical treatment.
18. I desire to add in conclusion that the doubts that I have heard expressed as to the unsuit- ability of the water for drinking purposes are absolutely without foundation. It is a matter for congratulation that the public have such an excellent supply-even although it does at times contain a minute quantity of inert mineral matter, occasioning a faint milky appearance-instead of being largely dependent as they were formerly on a number of shallow wells, which may have yielded a bright and sweet tasting water, but which were in too many instances charged with all kinds of organic filth in various states of decomposition.
E. W. LUCAS, Acting Apothecary and Analyst,
Government Civil Hospital, September 11th, 1891.
GOVERNMENT NOTIFICATION.-No. 396.
The following Return of the quantity of Spirits distilled at the Tiú Ün Sauce Factory, at Yaumati, is published.
Piculs.
Spirits manufactured during the 3 months ended 31st August, 1891, ...... 121
By Command,
Colonial Secretary's Office, Hongkong, 26th September, 1891.
W. M. GOODMAN, Acting Colonial Secretary.
GOVERNMENT NOTIFICATION.-No. 397.
Tenders will be received at this Office until Noon of Thursday, the 1st proximo, for repairs, &c. to the Post Office Steam-launch Courier.
A list of defects and necessary repairs may be seen at the Office of the Government Marine Surveyor, to whose satisfaction the work will have to be carried out.
The successful tenderer must provide a suitable launch, during the repairs, for the use of the Post Office, and also be responsible for the Courier while the repairs are being effected and until she is handed back to the Government fit for service.
The Government does not bind itself to accept the lowest or any tender.
By Command,
Colonial Secretary's Office, Hongkong, 26th September, 1891.
W. M. GOODMAN,
Acting Colonial Secretary.