A manual of practical hygiene / by Edmund A. Parkes ; edited by F.S.B. Francois de Chaumont.

Date:
1887
Catalogue details

Licence: Public Domain Mark

Credit: A manual of practical hygiene / by Edmund A. Parkes ; edited by F.S.B. Francois de Chaumont. Source: Wellcome Collection.

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

    787/838 (page 735)
    (c) Copper Sulphate Solution.—Dissolve 30 grammes of pure copper sulphate in 1 litre of distilled water. (d) Metallic Zinc, pure.—As thin foil. This should be kept in a dry atmo- sphere, so as to be preserved as far as possible from oxidation. To nmiie the wet Copper Zinc couple.—Put into a flask or bottle a piece of clean zinc foil, and cover it with the copper solution (c): allow the foil to remain until it is well covered with a firmly adhering black deposit of copper. (If left too long the deposit may peel oft' in washing.) Pour off the solution (which may be kept for further use), and wash the conjoined metals with distilled water. The couple is now ready for use. About one square decimetre ( = J of a square inch) should be used for every 200 c.c. of a water containing 5 parts or under of nitric acid in 100,000. For waters richer in nitrates more will be required. (e) Standard Solution of Ammonium Chloride (see 4 (a)). (J) Nessler^s Solutio7i (see 4 (6)). , 6. Reagents for the determination of Nitrous Acid in Nitrites. (a) Solution of Meta-pheriylenediamine.—Dissolve 5 grammes of meta-phenylene- diamine in 1 litre of distilled water, rendered acid with sulphuric acid.. Decolorise, if necessary, with animal charcoal. (6) Dilute Sulphuric Acid.—One volume of pure sulphuric acid to two volumes of distilled water. (c) Solution of Potassic Nitrite.—Dissolve 0-406 gramme of pure silver nitrite in hot water, and decompose it with a slight excess of potassium chloride. After cooling, make the solution up to one litre, allow the chloride of silver to settle, and dilute each 100 c.c. of the clear supernatant liquid again to one litre. 1 c.c. of this diluted solution = O'Ol of a milligramme of NO2. The nitrites may also be determined by the permanganate solution (see 3). 7. For determination of Phosphoric Acid. One part of pure molybdic acid is dissolved in 4 parts of ammonia, sp. gr. 0-960. This solution, after filtration, is poured, with constant stirrino-, into 15 parts of nitric acid of 1-20 sp. gr. It should be kept in the dark' and carefully decanted from any precipitate that may form. ' 8. Sulphuric Acid Solution for Carbonates in Water. Take 4-9 grammes by weight of pure H2SO4 and dilute to 1 litre. 1 c.c. saturates 5 milligrammes of calcium carbonate. „ „ 6-2 „ of sodium „ 9. Alkaline Solution for Acidities. Take liquor sodse or liquor potassse of pharmacopoeial strength, and dilute with 8 or 9 parts of distilled water. Graduate with oxalic acid solution (a). (See No. 7.) 1 c.c. of standard alkaline solution = 6-3 mgm. oxalic acid. = 6'0 „ glacial acetic acid. = 9'0 „ lactic . = 7'5 „ tartaric „ = 6'4 „ citric „ . 10. Oxalic Acid Solutions. Solution (a)—Take 6-3 grammes of crystallised oxalic acid, and dissolve in one litre of water. 10 c.c. exactly neutralise 10 c.c. of standard alkaline solution.