PREFACE, IX examined by chemical experiments. This Work, I with to be underflood, . is not meant to give an account of all the different Theories^-and their hiflory, as thefe may be better taught occafion- ally in Lectures, or may be read in fe- veral books publifhed on that fubjcct, to which I refer. It is merely to be confidered as a Collection of the bell eflablifhed Fafts in Chemiflry, arranged in an order, which from experience, I thought the mofl proper for beginners in Chemiflry, and eafiefl to be under flood. It will be very ufeful for Un dents who attend Leftures, and even for fuch who wifh to make application of their obtained knowledge, in per forming experiments themfelves. The method which I have adopted, will not interfere with the utility of attending Lectures on Chemiflry, though thefe may