Note 23 — The Correlation of Vital and Physical Forces.
Reading edition
Liebig, Justus von, Die organische Chemie in ihrer Anwendung auf Physiologie und Pathologie, Braunschweig, 1842. Also in his Animal Chemistry, edition of 1852 (Am. ed., p. 26), where he says “Every motion increases the amount of organized tissue which undergoes metamorphosis.”