Conversations on chemistry ; in which the elements of that science are familiarly explained. And illustrated by experiments, and sixteen copper-plate engravings. The ninth American from the eighth London edition, revised, corrected and englarged ; To which are now added, explanations of the text--questions for exercise--directions for simplifying the apparatus, and a vocabulary of terms--together with a list of interesting experiments ; By J.L. Comstock, M.D | lit.salon