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

  • Adam Walker
Date:
[1795?]
Catalogue details

Licence: Public Domain Mark

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

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    form a very ftrong magnet.—If a piece of iron, as a conduce tor^ be put between the two poles, the magnet will long retain its virtue, particularly if it hangs loofe fo as it can turn north and fouth.—Lay four fmall bars of Heel touch- ing one another in a line, lengthwife ; Hide one pole of a magnet from the right hand to the left over them feveral times, and they will be good magnets: But if then you Hide the fame pole over them from the left hand to the right, the magnetic virtue will be entirely taken from them. Fire and ruft dellroy the power of thefe magnets, and time will vreaken them, if a condudlor of iron or Heel do not form a magnetic circuit for the effluvium to pafs through. To recal the decreafed virtue of a mag- net, hang a largeyaW-^<*_g-to the iron adhering to it, and keep every day increafing the fand.—To give the virtue to a knife^ draw it over either pole from hilt to point fe- veral times. By fire, is underftood a complex idea of fomething red^ Jh'mingy that excites the fenfation of heat, and rarefies or expands all known bodies. It is the moft powerful agent in the decompofition of bodies. It is the only efJentiaL fluid in nature, and the caufe of fluidity in other bodies, by feparating their parts ; hence, even air itfelf may be- come folid when deprived of the fije it contains, as bodies of the moft difficult fufion become fluid when penetrated by. a fufficient quantity of the particles of fire. All bodies become hot by the approach of ignited bodies, and by friftion ; but bodies that contain a fufficient- quantity of phlogifton, only, are capable of inflamma- tion. Phlogifton is not fire, but one of the principles of inflammability; i. e. when it is combined with various fubftances in due proportion, it renders them inflamma- ble with air Phlogifton may be feparated from one body, and given to another ; hence an inflammable body may be 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 C
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