An examination of Dr. Crawford's theory of heat and combustion / by William Morgan.

  • Morgan, William, 1750-1833.
Date:
1781
Catalogue details

Licence: Public Domain Mark

Credit: An examination of Dr. Crawford's theory of heat and combustion / by William Morgan. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

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    fire in greater quantities than others. Thefe different powers he calls the capacities of bodies for containing heat.—In determining the com- parative quantities of heat in bodies, his Expe- riments led hy*i to conclude that atmofpherical ,and dephlogifticated air have much more of this principle than Fixed and Phlogifticated air, and that the quantity of heat in airs of different kinds is in proportion to their purity.— Following the fame method of making his Ex- periments on more folid bodies. Dr. C. is further led to maintain that Metals have leTs heat than their Calces, * and uniting this to the fa£t juft mentioned refpe&ing air, he lays down this general law ; “ That bodies when joined to u phlogifton contain lefs abfolute heat than “ when they are feparated from it,” and there- fore, “ that if phlogifton be added to a body, *f a quantity of the abfolute heat of that body “ will be extricated ; and if phlogifton be fe- “ parated again, an equal quantity of heat * It may not be improper to obferve here, that thofe cakes are the earthy parts of the metals feparated from their phlogifton.—And that Atmofpherical and Dephlo- gifticated Airs, are fuppofed to be more or lefs pure as they are more or lefs free from this principle. An atten- tion to thefe particulars will render the extra&s which follo.w from Dr. C’s. Treatife more intelligible. “ will