Note 389 — PHARMACOLOGIA. (continued 2)

This is particularly the case with respect to the water of the River Thames; for as it contains but a small proportion of saline matter, it is remarkably soft, although it holds suspended mud, and vegetable and animal debris, which occasion it to undergo a violent change on being kept: a large volume of carburetted and sulphuretted hydrogen gases is evolved, and it becomes black and insufferably offensive; upon racking it off however into large earthen vessels, and exposing it to the air, it gradually deposits a quantity of black slimy matter, and becomes as clear as crystal, and perfectly sweet and palatable, and is exceedingly well adapted for sea store. “The New River Water” contains a small proportion of muriate of lime, carbonate of lime, and muriate of soda; it differs also in its gaseous contents: 100 cubic inches of New River Water contain 2·25 of carbonic acid, and 1·25 of common air, whereas the water of the Thames contains rather a large quantity of common air, and a smaller proportion of carbonic acid.