. . .thers imagine, then such sulphureous bodies, when ignited, should rarefy and dilute all the circumambient air; whereas it is found by many of the preceding experiments, that acid sulphureous fuel constantly attracts and condenses a considerable part of the circumambient elastick air: an argument that there is no fire endued with peculiar properties inherent in sulphur; and also that the heat of fire consists principally in the [Pg 34] brisk vibrating action and re-action between the elastick repelling air and the strongly attracting acid sulphur, which sulphur in its Analysis is found to contain an inflammable oil, an acid salt, a very fix’d earth, and a little metal.”

Enough has now been said to give a fair idea of Stephen Hales’ researches. It will suffice if his conclusions be stated in his own words (p. 314):—

“Thus, upon the whole, we see that air abounds in animal, vegetable, and mineral substances; in all which it b. . . Read More