With experiments on man, there is a constant transformation of solid
body material into gaseous products which are carried out into the
air-current and absorbed. Particularly where no food is taken, this
solid material becomes smaller in volume and consequently additional
oxygen is required to take the place of the decrease in volume of body
substance. But this so-called respiratory loss is more theoretical than
practical in importance, and in the experiments made at present the
correction is not considered necessary.