An analysis of the mineral water of Tunbridge Wells, with some account of its medicinal properties / by Charles Scudamore. To which are annexed some observations on the water with which Tunbridge Wells is chiefly supplied for domestic purposes. By Thomas Thomson.

  • Scudamore, Charles, 1779-1849.
Date:
1816
Catalogue details

Licence: Public Domain Mark

Credit: An analysis of the mineral water of Tunbridge Wells, with some account of its medicinal properties / by Charles Scudamore. To which are annexed some observations on the water with which Tunbridge Wells is chiefly supplied for domestic purposes. By Thomas Thomson. Source: Wellcome Collection.

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    any possibility that the substance which is to bo » examined contains iron, they are objectionable, as they have the property of forming a dark pre¬ cipitate with that metal, which might be very readily mistaken for lead. For example, they would lead to a fallacious inference, if employed in the case of this water of Tunbridge Wells ; for although the proportion of iron which it con¬ tains is exceedingly minute, and so much so as not to affect its properties as a pure domestic water, still, after being much concentrated, it discovers the presence of iron, by these and other re-agents. 3.—The hydriodate of potash, which has been recently recommended as a re-agent to detect the presence of lead, is too ambiguous to be in the least depended upon. It sometimes preci¬ pitates lead, orange, and sometimes white. If there be the least excess of acid present, the iodine itself is thrown down, and bare exposure to the atmosphere for some time occasions a red tinge, which is sometimes even yellowish. Iron and tin are thrown down yellow, as well as lead ; and I have sometimes produced a yellow preci¬ pitate by means of this re-agent, when no metal whatever was present. Hydriodate of potash, then, though a good negative proof of the absence of lead, cannot be employed with safety to ascer¬ tain its presence.