Water analysis for sanitary purposes : with hints for the interpretation of results / by E. Frankland.

  • Edward Frankland
Date:
1890
Catalogue details

Licence: Public Domain Mark

Credit: Water analysis for sanitary purposes : with hints for the interpretation of results / by E. Frankland. Source: Wellcome Collection.

Provider: This material has been provided by London School of Hygiene & Tropical Medicine Library & Archives Service. The original may be consulted at London School of Hygiene & Tropical Medicine Library & Archives Service.

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    operation has been successfully conducted, the mass should consist of greyish-black grains, destitute of metallic lustre. It the zinc tilings retain their form, the heating has not been cai’ried far enough. If, on the other hand, the mass presents the appearance of half fused shot, with a yellowish brassy tint, the heating has been carried too far—the metals have become alloyed, and will bo electrolytically inert. As soon as the proper point has been reached, the flask is removed from the flame, the agitation, however, being continued for a few seconds, to prevent fusion. The point of the capillary tube is then sealed np, and the whole is allowed to cool. C.—FOR ESTIMATION OF NITRITES (GRIESS’S METHOD). Meta-'phen]ilenediamine. (^Meta-diamidn-henzol, fusing point 03“ C.)—Dissolve 5 grams of the base in a litre of water and slightly supersaturate with sulphuric acid. Dilute Sulphuric Acid.—One of pure acid to two of water. Standard Potassic or Sodic Nitrite Solution.—A solution of alkaline nitrite, of which I c.c. is equivalent to O'OI mgrm. nitrous anhydride (N2O3), prepared thus:—Dissolve 0406 gi*am of pure silver nitrite in boiling distilled water, and add pure potassic or sodic chloride till no more argentic chloride is thrown down. Make np to one litre, let the argentic chloride settle, and dilute 100 c.c. of the clear solution to one litre. This solution should be kept in closely-stoppered bottles quite full. D.—FOR ESTIMATION OF CHLORINE. Standard Silver Solution.—Dissolve 2'3944 grams of argentic nitrate in a litre of distilled water. In use, it is convenient to measure it from a 10 c.c. burette graduated into tenths. Potassic Chromate Solution.—A strong solution of pure neutral chromate, fi’ee from chlorine. It is best to deliver it
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