POLYATOMIC ALCOHOLS, The term alcohol, originally limited to one substance— viz., spirit of wine, or hydrated oxide of ethyl, has begun to be applied to a considerable number of organic compounds, many of which, in their external characters, bear little resemblance to common alcohol. Most of them are fluid and volatile, some of them are combustible, and all of them are composed of carbon, hydrogen, and oxygen, behave in a precisely similar manner toward the same decomposing agents, and are perfectly neutral to test-paper.
Every alcohol, when acted on by oxidizing agents, loses two equivalents of hydro gen, and is converted into an aldehyde; and by the prolonged action of the oxidizing Kent, the aldehyde takes up two equivalents of oxygen, and is converted into a special acid. Moreover, all alcohols, by the abstraction of the elements of water, yield ethers. Hence, every alcohol has its own ether, aldehyde, and special acid; the aldehydes of the alcohols termed poly-atomic, have, however, not been formed.
According to the theory of organic radicals, the alcohols are hydrated oxides of an alcohol radical. Thus, common alcohol, or spirit of wine, is the hydrated oxide of the radical ethyl (COL), and is represented by the formula HO; similarly, wood spirit is the hydrated oxide of the radical methyl (C4H4), and is represented by the formula According to the theory of chemical types (see TYPES, CHEMICAL), the alcohols are divided into monatomic and polyatomic. A molecule of water consists of
two atoms of that substance, and is therefore represented by the formula which may be arranged in the form H O. If half the hydrogen in this typical formula be replaced by an organic radical, such, for example, as or (a being even in all these cases), we obtain what is termed a monatomic alcohol one equivalent of hydrogen being here replaced. Besides the primary water-type repre sented by one molecule of water, there are derived or secondary and tertiary types, represented by two and by three molecules of water, and expressed in the forms and He ? O. If half the hydrogen in H. . be replaced by an organic radical, we obtain an alcohol said to be diatomic, in consequence of its being formed by the replacement of two equivalents of hydrogen. Similarly, if half the hydrogen in be replaced by an organic radical, we obtain a triatomic alcohol. The term polyatomic is applied to all alcohols which are not monatomic.