Air and rain : the beginnings of a chemical climatology / by Robert Angus Smith.

  • Robert Angus Smith
Date:
1872
Catalogue details

Licence: Public Domain Mark

Credit: Air and rain : the beginnings of a chemical climatology / by Robert Angus Smith. Source: Wellcome Collection.

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    air; and of these there are two mainly found in the atmosphere, although there are others in small quantities. Of these latter, one, namely, carbonic acid, influences all the neighbourhood of men and animals, and wherever combustion takes place, whilst hydrogen and its compounds are the consequence of frequent natural phenomena. Besides these, the increasing activity of manufactures brings before us prominently the fact that gases are formed in abundance, and some of them deleterious to plants and animals, being at the same time offensive to the senses. When we have learnt how numerous these gases are which may be found in the air, we have still to consider the number of vapours. These arise in unknown quanti¬ ties, and, we may also say, with unknown qualities, from the agreeable scent to the most unpleasant and noxious effluvium. Even then we have not recounted all the substances in the air. We know that there are solid particles. These consist partly of well-known, but partly of unknown sub¬ stances. We have common salt and sulphate of soda, we have nitrate of ammonia, and, in times, at least, lime, salts, and iron. We have also phosphates, and, no doubt, in small quantities, iodides, and probably a little of every¬ thing at times, which in minute quantities the sea or the r surface of the land may contain. Besides these inorganic substances we have the organic, which have come from animals and from vegetables—the debris of living things. To add to the organic substances, we have those which are organised, living things themselves, and capable of plant¬ ing colonies wherever they can find food and comfort. These latter may probably be divided into many kinds—the useful and the deleterious, those which promote health and those which bring disease. The idea of any of them bringing health is not founded on anything positive, but we can scarcely imagine these numberless forms to be all
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