What takes place when alkalies and acids are brought together? We will now examine the ashes left after burning vegetable substances. This we have called inorganic matter, and it is obtained from the soil. Organic matter, although forming so large a part of the plant, we have seen to consist of four different substances. The inorganic portion, on the contrary, although forming so small a part, consists of no less than nine or ten different kinds of matter.[B] These we will consider in order. In their relations to agriculture they may be divided into threeclasses— alkalies, acids, and neutrals.[C].
