Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: it through a state of being a molten mass at a white heat, there could not have existed plant or animal life until relatively recently, when it had cooled off at the surface. Possibly for this reason and because of its greater simplicity, inorganic chemistry was studied first and has first place in all discussions of chemistry that are complete in their scope. textit{Inorganic chemistry is essentially mineral chemistry. Most of the inorganic elements usually occur combined in nature. Oxygen occurs uncombined in the air, although mixed with nitrogen. Sulphur occurs free in a few places because of volcanic or similar action. In the cases of the metals, only a few are found in the free state, such as copper (in a few localities), and the so-called noble metals— silver, gold, and platinum—are quite apt to be found in the free state, .as they are not very subject to atmospheric influences. textit{Organic chemistry is the study of the composition, properties, and changes undergone in substances of animal or vegetable origin. Organic chemistry is essentially the study of the textit{compounds of carbon. They are composed largely of compounds of carbon and hydrogen, with or without other non-metallic substances, such as oxygen, nitrogen, chlorine, sulphur, etc., and only occasionally a metal may be in combination. One of the early lessons we had at school was tha.t there were three great divisions of matter,—animal,vegetable, and mineral. We might combine this classification with a simple chemical one: Animal ) f Non-metale ) Organic Mineral textit{( Inorganic Vegetable) ( Metals ) Organic substances can generally be distinguished from inorganic ones by means of heat in the presence of air at a burning temperature. Organic substances are consumed, while nearly all inorg...