hydrocarbon (hi-dro-kar'bon)

A compound of carbon constitute a number and of hydrogen. homologous The h's series, each member of each series being formed from the preceding member by the addition of the common difference CH2. Consequently, in each series, the relation between the number of hydrogen and the number of carbon atoms in each member is the same; and this relation may accordingly be expre ed by a general formula which will represent every member of that particular series. There are several cla es of h's, namely, the saturated (paraffins, fatty h's), the unsaturated, the poly methylene, and the aromatic, normal h. A h. which has its carbon atoms united to form an unbranched chain. [Gr., ydor, water, + Lat., carbo, coal.]