What is "inogen"

Inogen \In"o*gen\, n. [Gr. 'i`s, 'ino`s, a muscle + -gen.] (Physiol.) A complex nitrogenous substance, which, by Hermann's hypothesis, is continually decomposed and reproduced in the muscles, during their life.

n. (context organic compound obsolete English) A complex nitrogenous substance formerly hypothesized to be continually decomposed and reproduced in the muscles during life.