Manual of the medicinal preparations of iron : including their presentation, chemistry, physiological action, and therapeutic use / by Harry Napier Draper.

  • Draper, Harry Napier.
Date:
1864
Catalogue details

Licence: Public Domain Mark

Credit: Manual of the medicinal preparations of iron : including their presentation, chemistry, physiological action, and therapeutic use / by Harry Napier Draper. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

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    of potassium. A small quantity boiled with an excess of caustic soda and filtered, gives, when exactly neutralized by nitric acid, a brick-red precipitate on the addition of solution of nitrate of silver. Tests The solution in hydrochloric acid when diluted, gives no precipitate with chloride of barium. Twenty grains dissolved in an excess of hydrochloric acid, diluted with water, continue to give a blue precipitate with the ferridcyanide of potassium, until at least seventeen measures of the volumetric solution of bichromate of potash have been added. [The object of adding acetate of soda to the arseniateof soda in this formula is to replace by acetic acid an equi- valent of sulphuric acid set free in the decomposition. Arseniate of iron is dissolved by sulphuric acid, and inso- luble in acetic acid. The product would be deficient in quantity without this precaution. The following equation represents this decomposition :— 3 (Fe O, SO3) + 2 NaO, HO, AS 0,=3 Fe 0, As +2 (Na 0, 803)+HO, SO3 The absence of a precipitate on the addition of chloride of barium to the hydrochloric acid solution of course in- dicates that no trace of sulphuric acid or a sulphate is present. The employment of a standard solution of bichromate of potash in the examination of this and other preparations of protoxide of iron is based upon the definite oxidizing action of the bichromate, the litre of the solution being such that it is easy to calculate from the number of mea- sures used the quantity of protoxide of iron present in any compound.]
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