CHEMICAL TREATISE ON AIR AND FIRE. 1. It is the object and chief business of chemistry to skilfully separate substances into their constituents, to discover their properties, and to compound them in different ways. How difficult it is, however, to carry out such operations with the greatest accuracy, can only be unknown to one who either has never undertaken this occupation, or at least has not done so with sufficient attention. 2. Hitherto... more...