846 . ANIMAL HEAT. 
For experiments on man, Currie, 1 and afterwards Liebermeister 2 and others, 
used a bath as a water calorimeter ; this method is liable to many sources of 
error. Scharling, 3 Vogel, 4 and Hirn 5 used a method which was simple, bnt at 
the same time untrustworthy ; the subject of the experiment was enclosed 
within a small chamber standing in a room with a constant temperature ; the 
production of heat was determined from the difference between the tempera- 
ture of the chamber and that of the room. Leyden employed a partial 
calorimeter for experiments in man ; a limb was enclosed in a suitable water 
calorimeter. 
It is probable that the simplest and most useful method for clinical 
purposes is that introduced by Waller 6 ; the deep and surface temperatures 
of different parts of the body are determined, the evaporation of water from 
the skin is estimated by a hygrometer, and the temperature of the surrounding 
air is noted. If the calorimetric value of the thermometer scale be pre- 
viously determined on a surface giving off heat at a known rate, it is possible 
from the data obtained to calculate the emission of heat. The apparatus, in 
fact, constitutes a heat manometer measuring the temperature difference 
between the skin and atmosphere. 
The results of calorimetric experiments. — Lavoisier 7 and Craw- 
ford 8 concluded from their results that the heat produced by an animal 
could be almost entirely accounted for by the combustion represented 
by the discharge of carbon dioxide and water. Dulong 9 and Despretz's 10 
data, when corrected by Liebig, n Helmholtz, 12 Gavarret, 13 Ludwig, 14 Milne 
Edwards, 15 and Liebermeister, 16 lead to a similar conclusion, but since the 
more exact experiments of Rubner and others, they have had only a 
historical interest. 17 
The table on p. 847 gives some of the more important results 
obtained by various observers. 
It has been already shown that the heat, measured directly with a 
calorimeter, is equal to that calculated from the heats of combustion of 
the constituents of the food (Eubner 18 ), and it will be seen later that the 
production of heat in different warm-blooded animals is proportionate to 
the surface of their bodies (Rubner). 19 During digestion and muscular 
work the production of heat is greatly increased. 
According to Langlois, 20 the production of heat in children is pro- 
portionate to the surface of their skin, and shows a daily variation. 
1 " Medical Reports on the Effect of Water, Cold and Warm, as a Remedy in Fever and 
other Diseases," Liverpool. 1798. 
2 Arch./. Anat., Physiol, u. wissensch. Med., 1860, S. 520, 589 ; 1861, S. 28 ; " Hand- 
bnch der Path. u. Therap. des Fiebers," 1875, S. 142. 
3 Journ. f. prakt. Chem., Leipzig, 1S49, Bd. xlviii. S. 435. 
4 Arch. d. Ver. f. wissensch. Heilk., Leipzig, 1864, S. 442. 
5 " Recherches sur 1* Equivalent mecanique de la chaleur, " Paris, 1858. 
6 " Proc. Physiol. Soc," Journ. Physiol., Cambridge and London, 1894, vol. xv. 
7 Hist. Acad. roy. d. sc, Paris, 1780, p. 355. 
8 " Experiments and Observations on Animal Heat," 1788, 2nd edition. 
9 Ann. d. chim. etphys., Paris, 1843, Ser. 3, tome i. p. 440. 
10 Ibid., 1824, Ser. 2, tome xxvi. p. 337. 
11 "Thierehemie."S. 28. 
12 "Encyclop. Worterb. d. med. Wissensch.," 1846, Bd. xxxv. S. 523. 
13 " De la chaleur prodnite paries etres vivants," 1855, p. 219. 
14 "Lehrbuchd. Physiol.," 1861, Aufl. 2, Bd. ii. S. 739. 
15 " Lecons sur la physiologic," 1863, tome viii. p. 23. 
16 "Handbueh der Path. u. Therap. des Fiebers," 1875, S. 134. 
17 For a discussion of these results see Rosenthal, Hermann's "Handbuch," Bd. iv. Th. 2, 
S. 358. 
18 Ztschr. f. Biol., Miinchen, 1894, Bd. xxx. S. 135. This article, pp. 833-37. 
19 Ztschr. f. Biol., Miinchen, 1883, Bd. xix. S. 535. This article, p. 853. 
20 Centralbl.f. Physiol., Leipzig ti. Wien, 1887, S. 237. 
