Dr. Pereira's Elements of materia medica and therapeutics : abridged and adapted for the use of medical and pharmaceutical practitioners and students and comprising all the medicines of the British Pharmacopœia, with such others as are frequently ordered in prescriptions or required by the physician / edited by Robert Bentley and Theophilus Redwood ; with an appendix.

  • Jonathan Pereira
Date:
1874
Catalogue details

Licence: Public Domain Mark

Credit: Dr. Pereira's Elements of materia medica and therapeutics : abridged and adapted for the use of medical and pharmaceutical practitioners and students and comprising all the medicines of the British Pharmacopœia, with such others as are frequently ordered in prescriptions or required by the physician / edited by Robert Bentley and Theophilus Redwood ; with an appendix. Source: Wellcome Collection.

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    nate of ammonia is a constituent of the atmosphere, and is, there- fore, found in rain water. Ammonia is found in vegetables in small quantities only, but is developed during the decomposition (sponta- neous or artificial) of most vegetable substances, as gluten. It is one of the bases found in the urine of man, where it exists in com- bination with phosphoric, hydrochloric, and uric acids. Ammonia is also a product of the putrefaction of animal matters. Preparation.—Ammoniacal gas is obtained by heating a mix- ture of one part of powdered sal ammoniac and two parts of dry quicklime in a glass retort, the products being ammonia, chloride of calcium, and water. 2NH4C1 + CaO = CaCl2 + H20 + 2NH3. Properties.—Ammonia is a colourless invisible gas, having a strong and well-known odour. It reddens turmeric paper, and changes the colour of violet juice to green ; but by exposure to the air, or by application of heat, both the turmeric paper and violet juice are restored to their original colour. The specific gravity of this gas is 059. Ammoniacal gas is not a supporter of combustion, but is slightly combustible in the atmosphere, and, when mixed with air or oxygen, it forms an explosive mixture. Every two volumes of it require one and a half volumes of oxygen for their complete combustion. The results of the explosion are a volume of nitrogen and some water. It forms white fumes when brought into contact with hydrochloric acid gas, or chlorine. Dissolved in water, it communicates a deep blue colour to the salts of copper; throws down with the bichloride of platinum a yellow precipitate ; with chloride of mercury a white precipitate ; with protonitrate of mercury a black precipitate ; and with a concentrated solution of tartaric acid, a crystalline precipitate. It is extremely soluble in water and also in alcohol. [§ Liquor Ammonise Fortior. Strong Solution of Ammonia. Ammoniacal gas, 1STH3 or JNTH3, dissolved in water, and constitu- ting 32*5 per cent, of the solution.] Preparation.—[§ | Ammoniacal gas, produced from a mixture of sal ammoniac and slaked lime, is passed into distilled water contained in a Woulf's bottle under some pressure, until the liquid has the strength indicated by the tests.] [§ Characters and Tests-—A colourless liquid, with a character- istic and very pungent odour, and strong alkaline reaction. Specific gravity, 0'891. 52*3 grains by weight require for neutralisation 1,000 ©rain-measures of the volumetric solution of oxalic acid. One fluid drachm contains 15*83 grains of ammonia, KH3 or NH3. When diluted with four times its volume of distilled water, it does not give precipitates with solution of lime, oxalate of ammonia, sulphide of ammonium, or ammonio-sulphate of copper; and when treated