A Text-book of Chemistry: For Students and Practitioners of Medicine, Pharmacy, and Dentistry

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F. A. Davis Company, 1911 - Chemistry - 659 pages
 

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Page 603 - ... gm. of sodium sulphate, bringing the mixture to a boil, chilling and filtering to 20 cc To this filtrate there is now added a mixture of phenylhydrazin hydrochlorate 0.80 gm., sodium acetate 2.0 gm. and of 50 per cent, glacial acetic acid 1 cc, and the whole is boiled on a sand bath for ten minutes. The solution is then filtered while hot, and set aside to crystallize. The precipitation of crystals, sometimes only in microscopic quantities, of the characteristic formation of ozazones, makes a...
Page 39 - When one medium is a vacuum, n is the ratio of the sine of the angle of incidence to the sine of the angle of refraction. retardation, S — optical path difference between two beams in an interferometer; also known as "optical path difference
Page 373 - ... health, except as it may contain sulphuric and sulphurous acids, used in its manufacture and not completely removed. Cheap confectionery was composed largely of glucose and starch colored with anilin dyes. The use of paraffin in butter scotch and chocolates is dangerous, because of its insolubility. Foreign mineral contamination, accidental or surreptitious, is usually negligible in quantity. Actual dirt is sometimes left purposely in truffles. One seldom encounters of late ground gypsum, talc,...
Page 377 - Viscogen," a sirup of lime (6£ per cent), was used to give body to creams. Mineral coloring matters are much more objectionable than vegetable. The oxides and salts of arsenic, copper, chromium, and lead are especially injurious, and have been found in confectionery, flour, cakes, and cheese. Copper sulphate and nickel salts give an intense green color to cucumber pickles and canned peas which are imported into this country. Stannous chlorid precipitates the coloring matters from sirups and gives...
Page 444 - According to Sajous, the entire nervous system is built upon the plan of fibrils containing blood plasma surrounded by a layer of myelin. The main constituents of these bodies, the oxygen of the plasma and the phosphorus of the myelin, are thus brought into contact, and nervous energy is liberated.
Page 378 - He holds that sterilization suffices for canned meat, and that grain spirit and the simple condiment substances (salt, sugar, spices, vinegar, wood smoke) in moderate quantities are the only unobjectionable added preservatives. One important objection to food preservatives is the stale condition which they hide, though not preventing the formation of autolytic enzymic products detrimental to health. Borax and boric acid have been extensively used in milk, cream, butter, meats, beef juice, broken...
Page 603 - After partly cooling, 8 gm. of lead carbonate are gradually added. When the reaction is complete, the mixture is chilled, filtered, and 10 cc of filtrate diluted to 20 cc with distilled water. This solution is precipitated with 2 gm.
Page 377 - ... found in confectionery, flour, cakes, and cheese. Copper sulphate and nickel salts give an intense green color to cucumber pickles and canned peas which are imported into this country. Stannous chlorid precipitates the coloring matters from sirups and gives a bright yellow appearance. Tea leaves were faced with lead salts or Prussian blue. Bleaching agents in food are of hygienic importance. Sulphurous acid (the fumes of burning sulphur) is used with dried fruits, starches, wines, and finished...
Page 378 - The question of the use of chemical preservatives in food has long been a storm center of controversy between sanitarians and manufacturers. Dr. HW Wiley, Chief of the Bureau of Chemistry, Department of Agriculture, the foremost authority upon this subject, declares that nearly all food preservatives (including borax, boric acid, sodium sulphite, and benzoic acid) used continually, have a deleterious effect upon digestion and are irritating to the kidneys. He holds that sterilization suffices for...

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