_Temperature._--Aside from the almost hourly fluctuations of the bodily temperature, a noticeable sinking of the temperature-curve is observed during the hours of sleep. This alone is sufficient to indicate a diminished rate of combustion in the tissues. Boussingault found[9] that a dove which consumed 255 millegrammes of carbon every hour while awake, oxidized only 162 millegrammes when asleep. Scharling also observed that the quantities of carbon successively oxidized by the same man when asleep and awake bore to each other the ratio of 1:1.237. The observations of Demme[10] indicate that increase of bodily temperature during the hours of sleep must be considered as the result of pathological processes in the tissues. The observations of Allix (_loc. cit._), made upon sixteen children during the first twelve days after birth, showed an average fall of 0°.38 C. during the hours of sleep. Eight children, between five and sixteen months old, exhibited a similar depression of 0°.56 C.; while ten children, ranging in age from twenty months to four years of age, averaged 0°.34 C. less when asleep than when awake. The well-known experiments of Chossat, who found that the temperature of pigeons was from 0°.70 C. to 0°.90 C. higher at noon than at midnight, may not be considered satisfactory evidence of the depressing influence of sleep, because it is true that the diurnal variations of temperature which are conditioned by the vital activities of every animal might be sufficient to account for these differences. The experiments of Horvath[11] are more convincing. This observer found that the marmots upon which he experimented were accustomed to sleep during the winter for about four days continuously, and would then remain awake for an equal length of time. “During the sleeping period they can be cooled down to such a degree that a thermometer introduced into the rectum to the depth of an inch and a half indicated only 3°F. above the freezing point. The temperature rose rapidly after the animal awoke, so that in the course of an hour it was 3°F. higher; at the close of the second hour 9°F. higher, and at the end of the next half hour about 27°F. * * Neither respiration nor the muscular movements were correspondingly augmented.” This observation clearly shows the powerful influence of cerebral activity upon the liberation of heat within the body.