Page:History of the Royal Society.djvu/311

 before them; That great depths of Air make a Blue, and great depths of Water a Greenish colour; That great depths or thicknesses of coloured Liquors do all look blackish (red Wine in a large conical Glass being of all reddish colours between Black at the top and White at the bottom.

'That most Vegetables, at one time or other, are greenish; and that as many things passing the Sun are blackned, so many others much whitened by the same: Other things are whitened by acid Fumes, as red Roses and raw Silks by the smoak of Brimstone.

'Many Metals, as Steel and Silver, become of various colours, and tarnish by the Air, and by several Degrees of heat.

'We might consider the wonderful variety of colours appearing in Flowers, Feathers; and drawn from Metals, their Calces and Vitrifications; and of the Colours rising out of transparent Liquors artificially mixed.

'But these things, relating to the abstracted nature of Colours, being too hard for me, I wholly decline; rather passing to name (and but to name) some of the several sorts of Colorations now commonly used in Humane affairs, and as vulgar Trades in these Nations; which are these; viz.

1. 'There is a whitening of Wax, and several sorts of Linnen and Cotton Cloths, by the Sun, Air, and by reciprocal effusions of Water.

2. 'Colouring of Wood and Leather by Lime, Salt, and Liquors, as in Staves, Canes, and Marble Leather,

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