The naturalist's and traveller's companion, containing instructions for discovering and preserving objects of natural history, etc / [Anon].
- John Coakley Lettsom
- Date:
- 1772
Licence: Public Domain Mark
Credit: The naturalist's and traveller's companion, containing instructions for discovering and preserving objects of natural history, etc / [Anon]. Source: Wellcome Collection.
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![/ 1 [ |7 ] ther, the moft a&ive come to be neutral and innocent. It is in few infiances that the exha¬ lations u.re not expofed to the means of mixture; and it is but feldom, comparatively, that effe&s are produced upon human bodies, although in a particular manner immerfed in this vitiated atmofphere. 1 here are, however, fome impregnations in the atmofphere, which daily experience fhews have confiderable influence on our bodies; for though they may not fenflbly aifedl the more robuft and ftrong, they certainly do the weak and delicate. ^ With a view to'inveftigate them more particularly, the following experiments were made in the beginning of Auguft, in the year 1769. Foi iome preceding weeks thp air had been generally warm and dry, and iftoftly free from wind; the evening on which I began to condenfe the atmofpherical moifture was calm, and clos’d a fine warm day ; the place where this moifture was colle&ed, was in a court about the centre of Gracechurch-ftreet. I. procured a large glafs globe perfectly clean on the outfide, into which I put a quantity of ice and fal ammoniac powdered; the globe thus pre¬ pared, was fufpended in the air about five yards from the furface of the ground; the coldproduced by the ice and neutral fait congealed the moifture of the air on the external furface of the globe in ~.' the](https://iiif.wellcomecollection.org/image/b30515555_0047.jp2/full/800%2C/0/default.jpg)
