Vietnam or Thailand ? Vote for the TOP Country of the Week !
Updated: May 25, 2025
This ink is to be used with a clean pen, and the writing when dry will become invisible. But if at any time it be washed over with the following mixture, it will instantly become black and legible. Put some quicklime and red orpiment in water, place some warm ashes under it for a whole day, filter the liquor, and cork it down.
In the first case are sulphurets of copper, and copper iron; in the second case are the series of sulphurets of lead, or galena, from various parts of the world; in the third case are specimens of sulphuret of bismuth, needle ore, or sulphuret of bismuth, copper, and lead, and sulphurets of mercury, or cinnabar, chiefly from Spain, the light variety of which is the bright vermilion used by artists; in the fourth case are the sulphurets of silver, the beautiful crystallised sulphurets of antimony, chiefly from Transylvania, and the delicate plumose antimony, or feather ore; in the fifth case are the sulphur salts, including the ruby, silver, &c.; and in the sixth case are the sulphurets of Arsenic, red orpiment, of which the best comes from Persia, cobalt glance, &c., bringing the series of sulphurets to a conclusion.
I know not, Pyrophilus, whether it be worth while to acquaint you with the ways that came into my Thoughts, whereby in some measure to explicate the first of the mention'd ways of making a Green; for I have sometimes Conjectur'd, that the mixture of the Bise and the Orpiment produc'd a Green by so altering the Superficial Asperity, which each of those Ingredients had apart, that the Light Incident on the mixture was Reflected with differing Shades, as to Quantity, or Order, or both, from those of either of the Ingredients, and such as the Light is wont to be Modify'd with, when it Reflects from Grass, or Leaves, or some of those other Bodies that we are wont to call Green.
Word Of The Day
Others Looking