The experiments of MM. Lavoisier and Laplace have shown the quantity of caloric produced by the combustion of different substances by the calorimeter, a table of which may be seen in Thenard. (_Traité de Chimie_, &c. t. i, p. 81). From this table it appears, that while a mixture of one pound of saltpetre with one pound of sulphur liquefied, by its combustion, thirty-two pounds of ice, one pound of hydrogen gas melted 313 lbs. phosphorus 100 lbs. and the same quantity of charcoal 96.351 lbs.; and by the detonation of a mixture of one pound of saltpetre with 0.3125 lbs. of charcoal (French weight) melted only 12 lbs. of ice. In the table of the elevation of temperature by the combustion of different substances, the caloric being communicated to water, (Thenard, _Traité de Chimie_, vol. i, p. 82), it appears, that by the combustion of equal weights of hydrogen gas, phosphorus, charcoal, and oak, the caloric produced was as follows: Hydrogen 23,400° Phosphorus 7,500 Charcoal 7,226 Oak wood 3,146 The reader may find some interesting calculations on this subject in Biot's _Traité de Physique_, &c. tome iv, p. 704, and 716. It appears also, that in the combustion of one pound of hydrogen gas, six pounds of oxygen were consumed, and according to Crawford's experiment the caloric given out melted 480 lbs. of ice. One pound of phosphorus requires for combustion one and a half pounds of oxygen gas; one pound of charcoal, 2.8; and one pound of sulphur, 1.36. See Thomson's _System of Chemistry_, vol i, p. 133. While noticing this subject we may remark, that in combustion heat and light, according to the Lavoiserian doctrine, are given out from the oxygen gas, while the oxygen unites with the combustible body: which has since been modified by supposing, that while caloric is evolved from the gas, the light is emitted from the burning body. There are some facts contrary to the received theory of combustion; that of _gunpowder_ furnishes one. We have also another instance in the combustion of oil of turpentine by nitric acid.