Proceedings of the American Academy of Arts and Sciences Volume 43
This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1908 edition. Excerpt: ...from a given portion of the sample with that produced by a definite quantity of a standard solution of arsenic. Bird 2 made a careful study of the conditions under which the arsenical stain on mercuric chloride paper may be best obtained and identified, with especial reference to the interference of the hydrides of sulphur, phosphorus, and antimony. Although his work is extremely suggestive of a quantitative application, he himself considers that the test is only approximately quantitative, in that the stain obtained from a given amount of substance, say beer, may be shown to be greater or less than the stain representing a fixed limit of arsenic for that amount. He also regards it as a true negative test. Treadwell and Comment3 compared the stain obtained from the action of arsine on argentic nitrate paper with a series of stains from definite quantities of a standard solution of arsenic. The method, applied by these authors to the detection of arsenic in mineral waters, is said to have given good results. Dowzard,4 after describing a modification of the Gutzeit test which allows the detection of minute traces of arsenic in a small volume of solution, suggested the preparation of a standard set of stains, which should be kept in a tightly stoppered bottle in a dark place. 1 Arsenical Poisoning in Beer Drinkers, p. 88. London, Balliere, Tindall, and Cox, 1901. 1 Analyst, 26, 181 (1901). Treadwell, Kurzes Lehrbuch der Analytischen Chemie, 2, s. 138 (1902). Chem. News, 86, 3 (1902). Thomson5 attempted to make the reaction quantitative by passing the arsenical hydrogen through a tube in which was hung a cotton thread or a paper, saturated with mercuric chloride solution, which, from the intensity of the stain produced upon it, should show...
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- 13 Sep 2013
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