But this malady occurs at Sumatra, where ice and snow are never seen ; while, on the contrary, the disease is quite unknown in Chili and Thibet, although the rivers of these countries are chiefly supplied by the

melting of the snow, with which the mountains are covered. Ice is said not to

quench thirst, but on the contrary to augment it, and that the natives of the Arctic regions prefer enduring the utmost extremity of this feeling, rather than attempt to

remove it by eating of snow,* ( Captain Ross.) 2. Spring Water. Rain water, when it falls on high grounds, enters the soil

and filtrates through it, until it is stopped by some natural obstacle, when it pushes upwards, and welling out upon the surface, forms springs ; the water is therefore

merely a modification of rain water. During its passage, however, it almost always takes up some soluble matters, which of course vary according to the nature of the

soil. It is purest when it passes through sand or gravel; in a limestone region, it

always contains more or less of the sulphate and carbonate of lime, and it generally contains a trace of common salt, and the usual proportions of air and carbonic acid

gas. The presence of these is detected by subacetate of lead, which displays the smallest portion of carbonic acid or a carbonate, and nitrate of silver, which detects

the muriates by the formation of muriate of silver.

Water from melted ice is perfectly wholesome, and is drunk during the summer season, wherever the climate will admit of its being collected and preserved at a