Elementary instruction in chemical analysis / By C. Remigius Fresenius, with a preface by Professor Liebig. Edited by J. Lloyd Bullock.

  • Carl Remigius Fresenius
Date:
1843
Catalogue details

Licence: Public Domain Mark

Credit: Elementary instruction in chemical analysis / By C. Remigius Fresenius, with a preface by Professor Liebig. Edited by J. Lloyd Bullock. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

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    ZINC. IRON. COPPER. for the latter substance, nearly the most susceptible reagent we possess. § 53. 17. zinc. (Zn.) Pure, sublimed zinc is selected for the purposes of chemical analysis; it must especially be free from arsenic. The method described in § 24 may be employed as a test to detect the pre- sence of any trace of this latter substance. The pure zinc should be fused, and a portion of it gradually dropped into a large vessel, containing water; the remainder should be poured into wooden moulds, coated with chalk, for the purpose of casting it ]! into little cylinders. Uses.—Zinc precipitates many metals in their metallic state, by depriving them of their oxygen and acid, owing to the great affinity it possesses for oxygen, and its oxide for acids. As tho precipitated metals vary in colour, form, &c., zinc may serve as well for their detection and distinction from each other, as for i their precipitation. We employ it especially for the precipitation • of antimony and of tin. Zinc is also frequently used for the pro- • duction of hydrogen. § 54. 18. iron. (Fe.) Iron, like zinc, reduces many metals, and precipitates them in a pure state. We employ it especially for the detection of cop- iper, which is precipitated on it with its characteristic colour. All i clean surfaces of iron, such as knife-blades, needles, pieces of wire, &c., are well adapted to this purpose. § 55. 19. copper. (Cu.) We employ copper exclusively for the reduction of mercury,