Hydrides.

Hydrides. This term is applied both to combinations of hydrogen with metals, and to similar combinations with organic or compound radicals. Hydrogen forms hydrides with a number of the metals, as, for instance, arsenic, antimony, copper, and potassium. The first two of these are the well-known gases, arseniuretred hydrogen, $\backslash text\{AsH\}\_3$, and antimoniuretred hydrogen, $\backslash text\{SbH\}\_3$. In the case of organic radicals, the hydride of ethyl, $\backslash text\{C\}\_2\backslash text\{H\}\_5\backslash text\{H\}$, for instance, was at one time supposed to be a different substance from dimethyl, $\backslash text\{CH\}\_3\backslash text\{CH\}\_3$, but these were eventually proved to be identical, so that the term hydride, in this sense, is now obsolete.