Analysis of a course of lectures on natural and experimental philosophy. Viz. 1. Magnetism, 2. Mechanics, 3. Chemistry, 4 & 5. Pneumatics, 6. Hydrostatics, 7. Electricity, 8. Fortification, 9. Optics, 10. Use of the globes, & c. 11 and 12. Astronomy / by A. Walker.

  • Adam Walker
Date:
[1790]
Catalogue details

Licence: Public Domain Mark

Credit: Analysis of a course of lectures on natural and experimental philosophy. Viz. 1. Magnetism, 2. Mechanics, 3. Chemistry, 4 & 5. Pneumatics, 6. Hydrostatics, 7. Electricity, 8. Fortification, 9. Optics, 10. Use of the globes, & c. 11 and 12. Astronomy / by A. Walker. Source: Wellcome Collection.

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    rated from lead, tin, &c. Acids and alkalies combine with mercury. Vapours of mercury and marine acid meeting, form chryhals like flattened needles, called corrofive JubUmate. Mercury fhook in vinegar, exhibits a curious phenomenon ; and it is luminous when fhook in vacuo. Quickfilver triturated with fulphur, forms Ethiops mineral; and this frequently fublimed, becomes cinnabar---or the vermilion of the painters. Cinnabar is alfo found a native in the mines, and may be confidered as the ore of quickfilver. EARTHS. Earths make up the folid part of our globe; they are fp intermixed, that it is difficult to come at their compo¬ nents, which are, ih. Calcareous earths, i. e. lime-hone5 chalk, haladlites, or hone icicles, marbles, or any earths that effervefce with acids; that fall in white powder when burnt; that will not melt into glafs by heat; but will melt when mixed with borax, or calcs’s, and affih the fufion of lead, copper, and iron. Siliceous earths, or pre¬ cious hones, as the diamond, ruby, topaz, opal, agate* cornelian, hint, jafper. Many of thefe hrike fire with, and even fcratch heel ;—do not melt with the hrongeh fire 5 and do not effervefce with acids. Argillaceous earths, or clays that harden in the fire, and ufed to make porcelain ; and clay marles, that moulder in wTater, and effervefce with acids, ufed as manure, Adicaceous earths are compofed of thin leaves, or lamina, with fhining fur- faces, and which divide into thinner leaves in the fire, and become brittle. JJbeftus earths. Thefe do not alter in the fibre ; are .flexible and hringy, capable of being fpun into threads, or wove into cloth. 'Zeolites are harder than calcareous hones 5 melt eafily. in the fire, with fwel- ling
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