SALT MANUFACTURE IN HONG KONG
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well acquainted with the Hong Kong area, and never saw those remains. In Hoifung I did not find any furnace or anything which could be referred to an ancient salt industry. In China the manufacture of salt has been of the greatest importance from the most ancient time. In the salt-lake districts (Shansi, Shensi, Kansu and Mongolia) the heat of the sun causes the salt to crystallise at the edge of the lakes and in some cases on the surface of the water. In Yunnan and Szechwan the brine is drawn up from the salt-wells and boiled in cauldrons. Boiling is rare in other provinces. At the sea-coast the salt-pan system is generally in vogue.
In the last issue of the Hong Kong Naturalist (Vol. X, No. 1) Mr. S. Y. Lin has published a good article on salt manufacture in Hong Kong. In Hoifung both the leaching and the ordinary method are practiced; at the bay of Tchanki.... the former is more common, and at the bay of Swabue only the latter is in use. The salt produced by the leaching method is somewhat refined; it is freer from soil and in fine crystals and is required therefore for kitchen use; but its production needs much more work and its price is greater, too. The salt produced by the ordinary system is coarser and more impure and is chiefly used for pickling and salting fish. People say that the latter salt is more bitter than the former. If this statement is true we must suppose that the mother-water is more easily over-saturated in the ordinary salt-pan method, so that magnesium sulphate can be produced along with sodium chloride. As here the salt season is principally in the dry autumn and winter and from mother-water saturated at over than 32°5 Baumé during cool nights the magnesium sulphate easily crystallises, likely much of our salt is really a mixed-salt.
Nowhere in our province, as far as I know, the boiling system is now in use, except occasionally by boat-men when it is impossible to buy salt. Here fuel is very expensive and scarcely sufficient for domestic purposes. Moreover, I note that on the granitic rocks at the sea-shore salt easily crystallises; ancient people may have collected it and so learned how to manufacture salt. Even at the present time some people gather salt by sweeping it from the rocks. However, the note of Dr. Heanley suggests a new field of research; indeed, many of our prehistoric sites are near modern salines or in a good position for salt-works.