Air and water : their impurities and purification / by Henry Bollman Condy.

  • Condy, Henry Bollman.
Date:
1862
Catalogue details

Licence: Public Domain Mark

Credit: Air and water : their impurities and purification / by Henry Bollman Condy. 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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    regarded rather as accidental than normal constituents. It is they which for the most \ art constitute the conta- minations of the atmosphere.* With few exceptions they are substances of an oxidizable nature. They consist of a great variety of more or less diffusible products, such as the gases generated by combustion and similar processes; traces of nitric, acetic, and sulphurous (or rather sul- phuric) acids, of nitrate, acetate, and hydrosulphate of ammonia, and in certain maritime situations, of mu- riatic acid and iodine; exhalations from the organic king- doms, morbid emanations from men, animals, and plants, when suffering from disease, and the results of their decomposition after death ; as well as of numerous forms of more or less tangible solid substances, such as carbona- ceous matter, infusoria and other microscopic organisms, pollen of plants, spores and germs of some low ordeitfof living beings, and finely subdivided inorganic matter. As even the latter group of bodies are invisible to the naked eye in ordinary diffused light, none of the above substances can be regarded as cognizable to the senses, except when they naturally possess or happen to acquire odorous properties. They then become perceptibly offen- sive, and cause the atmosphere in which they exist to be distinguished as bad or foul. It is principally the truly gaseous class of impurities which are possessed of smelling properties, although, on the one hand, some of them, and those not the least deleterious, such as carbonic oxide, are devoid of odour ; and on the other, some of the less diffusible atmospheric contaminations, such as ordinary bodily exhalations, which are not commonly perceptible to the nose, can be distinguished by persons of more than usual acuteness of smell, especially when proceeding from the bodies of the sick. The effluvia which certain wild animals leave on their tracks, and * Bouasingault; Complea liendus de i'Acad6mie des Sciences (1853) vol. xxxvii, p. 798.