the interposed water, the Focus fell upon the Pitch, wherein it would produce sometimes bubbles, sometimes smoak, and quickly communicated a degree of Heat capable to make Pitch melt, if not also to boil.
EXPER. X.
Though the first and second Experiments of Section I. shew, that a considerable degree of Cold is produc'd by the dissolution of Sal Armoniac in common water; yet by an additament, though but single, the Texture of it may be so alter'd, that, instead of Cold, a notable degree of Heat will be produced, if it be dissolved in that Liquor. For the manifestation of which we devis'd the following Experiment.
We took Quick-lime, and slaked it in common cold water, that all the igneous or other particles, to which its power of heating that Li- quor
