Foods: their composition and analysis : A manual for the use of analytical chemists and others. With an introductory essay on the history of adulteration / By Alexander Wynter Blyth. With numerous tables and illustrations.

  • Alexander Wynter Blyth
Date:
1882
Catalogue details

Licence: Public Domain Mark

Credit: Foods: their composition and analysis : A manual for the use of analytical chemists and others. With an introductory essay on the history of adulteration / By Alexander Wynter Blyth. With numerous tables and illustrations. 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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    Class II.—Water of medium purity, containing from O'l to 0-2 part of organic elements in 100,000. Class III.—Water of doubtful purity, containing from 0-2 to 0'4 part of organic elements in 100,000. Class IV.—Impure water, containing upwards of 0-4: part of organic elements in 100,000. APPENDIX TO WATER ANALYSIS. Standard Solutions and reagents &c.. Alphabetically Arranged. Parts by Weight: Liquids by Measure. §323. Amvionium Chloride.—Ammonium chloride, -3146 part; pure water, 1000 parts; dissolve. 1 cc. contains -00001 grm. of ammonia, or 10 grains contain -0001 grain. Calcic Chloride Solution.—Iceland spar, or other pure form of calcic carbonate, '2 part. Hydrochloric acid, q. s.; water, 1000 parts. The calcic carbonate is converted into chloride by evapo- rating to dryness with pure dilute hydrochloric acid, and the calcic chloride thus obtained is dissolved in water. The deter- mination of hardness is usually made by English chemists in grains per gallon; then the following are the proportions— Calcium carbonate 8 grains; fully convert by dilute hydrochloric acid, evaporate to dryness, dissolve in water, and make up to one-tenth of a gallon; dilute ten times its volume, and the result is water of 8°. Copper Sulphate.—Sulphate of copper 30 parts, pu.rc water 1000 parts; dissolve. Ferrous Chloride Solution.—A solution of pure ferrous sulphate is precipitated with sodic hydrate, and washed tlioroughly with pure water, and then dissolved in the smallest possible quantity of pure hydrochloric acid. Meta-phenylenediamine.—Meta-phenylenediamine 5 parts, water 1000 i^arts, sulphuric acid, q. s. Tliu base is dissolved in the water, and then slightly supersaturated witli sulphuric acid. Meta-phosphoric Acid.—Meta-phos])horic acid 100 parts, made up to 1000 with distilled water; 10 parts should contain no appreciable amount of ammonia. Molybdic Solution.—Molybdic acid, 1 part; solution of ammonia, specific gravity -900, 4 parts; nitric acid, 1-20 specific gravity, 10 parts. The molybdic acid is di.ssolvod in the ammonia, filtered, and ])ourcd with constant stirring into the nitric acid.
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