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.

  • Walker, A. (Adam), 1730 or 1731-1821.
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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    deprived of its inflammability, and a body naturally not inflammable, may be rendered fo by combining it with a fufficient quantity of phlogifton. When expel¬ led from bodies it is not annihilated—it only efcapes from the burning body into air, which gives proof of its having acquired it, and is then faid to be phlogijli- cated; and hence no inflammation will take place but in the common air. Combuftion ceafes when the air furrounding the burning body is filled with phlogifton— hence a fire is put out by blowing phiogifticated air into it --but enlivened by a current of frefh air. All bodies contain more or lefs of this wonderful principle—- for all bodies grow hot by violent fridtion ; fridtion. may be therefore faid to be a kind of fire-pump, that draws latent fire from the adjoining bodies to the place where the fridtion is going on, and ftrongly indicates that phlogifton may lie in a concrete form in, and be a conftituent part of all bodies y nay, Btrgman fays, 100 ounces of charcoal contains 99 ounces of phlogifton, and but one of earth \ and yet he affirms that phlogU fton is the caufe of volatility, as metals deprived of their phlogifton are heavier as a calcs than as a metal % inflammable air is eight or ten times lighter than com¬ mon air, &c. So little do we know of firer that any attempt at a theory of it muft appear prefumptuous and premature ; we find however that light y heat, and elec¬ tric fluid have fo many qualities in common with'phis- gijlon, that hereafter it may probably be found they are all but modifications of the fame principle. Rubbing, or friction, in all bodies produce heat and electricity^ and- 'both thefe dilate bodies, help vegetation, germination, evaporation, motion of the blood, the growth of the fetus3S and the hatching of eggs. Heat and electricity both re¬ duce, and melt metals ; and bodies that receive heat with difficulty receive electricityfkc. May not the rays of the fun be diluted phlogifton ? May not the velocity with which