Chemistry : general, medical, and pharmaceutical including the chemistry of the British pharmacopoeia a manual on the science of chemistry, and its applications in medicine and pharmacy / by John Attfield ; edited by Leonard Dobbin.

  • Dobbin Leonard.
Date:
1903
Catalogue details

Licence: In copyright

Credit: Chemistry : general, medical, and pharmaceutical including the chemistry of the British pharmacopoeia a manual on the science of chemistry, and its applications in medicine and pharmacy / by John Attfield ; edited by Leonard Dobbin. 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.

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    taining more nitrogen than the soil anti manure in which they grew. The absorption is effected by means of nodules which occur on the roots of clover and other leguminous plants; these are the dwelling-places of micro-organisms, and it is through their agency that the soil in which such plants grow becomes richer in nitrogen. Experiments have been made with a view to inducing these organisms to live on the roots of graminaceous plants, for if this could be done a great saving in artificial manures could be effected. Argon. Krypton. Neon. It has long been known that when nitrogen is prepared from atmospheric air, the gas obtained is slightly heavier than nitrogen prepared from nitrates or from ammonia. The investigations of Rayleigh and Ramsay have proved that this is due to the presence of another gas, heavier than nitrogen, to which, on account of its apparent chemical inactivity, they gave the name argon («, without, epyov, ergon, work). Its density is about 19. It is present in atmospheric air to the extent of nearly 1 per cent. Recently a compound of argon with carbon has been obtained by the passage of electricity between thin carbon poles in an atmosphere of argon; and experiments show that it probably combines with the vapour of magnesium at a very high temperature. Argon and helium occur with nitrogen in the gases of many naturally aerated waters. Ramsay obtained another element from atmospheric air, to which he gave the name Krypton (Kpv-nrros, kryptos, hidden) ; traces only are present. Ramsay and Travers subsequently announced the presence of another element, Neon (reos, neos, new), and Ramsay Xenon. CHLORINE Source.—The chief source of this element is common salt, more than half of which is chlorine. Preparation.—About a quarter of an ounce each of salt and of black manganese oxide are mixed, placed in a test-tube, and covered with water; on adding a small quantity of sul- phuric acid, evolution of chlorine commences. For the mode of collection see the following paragraphs.