Note 162-1 — Chapter III

Explained since Liebig's time by the fact that a part of food is consumed to preserve animal heat: means of respiration in contradistinction to means of nutrition. Recent research has shown that in cold weather more urea and also more carbonic acid are given off; hence the means of supplying this deficit should be greater in cold weather than in warm. This more rapid transformation is wont, when nutrition is sufficient, to be accompanied by more energetic activity. (Moleschott, Physiologie der Nahrungsmittel, 1850, 47, 50, 83.)