7 1 2 CHEMISTR V OF RESPIRA TION. 
made upon the influence of external temperature upon the respiratory 
exchange of warm-blooded animals. The general result of this work is 
that the intake of oxygen and the output of carbon dioxide increase 
with a fall and decrease with a rise of external temperature. This is 
shown by the examples, which have been taken from the results obtained 
by different observers, and are given in the preceding table. 
It appears that, when the external temperature is raised to a point 
about 30", the respiratory exchange shows an increase above the amount 
observed at a temperature of 20°. Thus Voit 1 found in the case of a 
man, that the output of carbon dioxide was increased by a fall of 9° or 
10" below the average temperature 14'-15 ; , and also increased by a rise 
of 15° or 16 3 above that point; the augmentation in the discharge of 
carbon dioxide was respectively 36 per cent, and 10 per cent, above" that 
given off at 14°-15°. A similar result was obtained by Page, 2 who 
found that at a temperature of 25° the discharge of carl ion dioxide by a 
dog was at a minimum ; a fall or rise of 10" below that point produced a 
mean increase of 31 per cent, and 51 per cent, respectively. 3 Unfortun- 
ately Voit gives no details as to the temperature of the man during 
the experiments, but in one or two cases Page notes that the tempera- 
ture of the clog was raised above the normal by exposure to the 
warm air. 
The earliest experiments upon the influence of external temperature 
on the respiratory exchange of man were made 1 >y Lavoisier and Seguin, 4 
who found that a man at rest absorbed in an horn' 34-49 grins, of 
oxygen when the air was 32°-5, but 38*31 grms. when the temperature 
was 15". Since that time many observations 5 have been made upon 
man and the effect of external temperature on his respiratory exchange, 
and of these the most important are those made by Lowy. 6 The 
general result drawn from his experiments is that the effect of" external 
cold varies in different men. Out of fifty-live experiments, the oxygen 
absorbed was increased above 5 per cent, in twenty-six cases, unaltered in 
twenty, and diminished in nine cases. In these experiments, in which the 
metabolism was increased, for the variations in the output of carbon 
dioxide followed those in the absorption of oxygen, the heights to which 
it was raised varied between 5 and 90 - 8 per cent, above the normal. A 
point worthy of note is that the greatest increase in the respiratory 
exchange was observed in the men who shivered or moved when they 
felt cold, and that the respiratory exchange remained unaltered or 
decreased in the men who, notwithstanding the sensation of cold. 
remained quiet, and by an effort of the will suppressed any tendency to 
move or shiver. Lowy concludes that the only involuntary regulator 
of temperature in a man exposed to moderate cold is the skin. It must 
be pointed out, however, that increased muscular activity in a man who 
1 Ztschr.f. Biol., iliinchen, 1878, Bd. xiv. S. 80. 
- Journ. Physiol., Cambridge and London, 1S79-S0, vol. ii. p. 228. 
3 See also Kubner, " Biologisehe Gesetze," Universitats-prograrum, Marburg. 1887; 
abstract in Ccntralbl. f. Physiol., Leipzig u. "Wien, 1887, S. 700. 
4 "CEuvTes de Lavoisier," tome ii. pp. 688, 704 ; Hist. Aead. roy. d. sc, Paris, 17S9, 
p. 575. See also Pep. Brit. Ass. Adv. Sc, London, 1871. p. 189. 
5 Vierordt, "Physiol, des Athmens," 18-15; E. Smith, Phil. Trans., London, 1859, 
vol. cxlix., p. 6S1 ; Speck. Schrift. d. Gesdlsch. z. Beford. d. gcs. Ndturw. zn Marburg, 
1S71, Bd. x. : Liebermeister, Dev.tschcs Arch, f. klin. Med., Leipzig. 1S72, Bd. x. S. 
420; Lehmann, Virchov's Archiv, 1873, Bd. lviii. S. 92. Johansson, Shrnrfin. Arch. f. 
Physiol., Leipzig, 1897, Bd. vii. S. 123. 
6 Arch. f. d. gcs. Physiol., Bonn, 1890, Bd. xlvi. S. 1S9. 
