ASPHYXIA IN A LIMITED QUANTITY OF AIR. 745 
the fact that the blood of the animal is generally arterial in colour. 1 
The fatal amount of carboD dioxide appears to be about 25 per cent. 
An Atmosphere containing an Excess of Oxygen and of Carbon Dioxide. 
Animal. 
Tempera- 
ture of 
1 las* -. 
Volume of 
i rases. 
Percentage 
Composition 
of Gases before 
the Experiment. 
Duration of Life. 
1 lomposition 
Of Oases at the 
time of Death. 
O... 
CO,. 
CO... 
O. 
Warm-Blooded — 
Rat, 1 month old. 
32 grms. 
Rat, 1 month old 
Rat, 3 days old, 
5 grms. 
Mouse, young, 
5 grms. 
Cold-Blooded — 
Grey lizard 
Frog . 
25° 
25° 
25° 
22° 
25°-29. 
25°-29° 
550 c.c. 
GOO ., 
150 ,, 
235 „ 
550 ,, 
550 ,, 
90 
75 
so 
90 
90 
90 
10 
25 
20 
10 
10 
10 
4 lirs. 
20 mil). 
More than 5 hrs. 
Mori- than 5 hrs. 
26 hrs. 
20 „ 
22-5 
26-5 
29-5 
24*5 
16 
17 
77-5 
73-5 
In the cold-blooded animals a marked difference is observed : death 
in such experiments is generally due to an excess of carbon dioxide, and 
the fatal percentage, about 16, is much lower than in the case of the 
warm-blooded animals. 
Important differences have also been observed by Edwards 2 and 
Paul Bert 3 in the duration of life, under water, of animals of different 
species, and in animals of the same species, but of different ages and 
exposed to various degrees of external temperature. See table on p. 746. 
The importance of these observations lies in the fact that they con- 
firm many of the results obtained by experiments upon the respiratory 
exchange of different animals. Thus an examination of the above tables 
shows that the small animals die more quickly than the big animals, 
and it has been proved that weight for weight they have a more rapid 
metabolism. 4 Further, a marked difference is observed in hens and 
ducks, for the latter can live under water three or four times as long as 
the former. The explanation of this fact is, according to Paul Bert, 5 to 
be found in the relatively greater quantity of blood in a duck. A 
similar condition appears to obtain in the seal and whale, 6 which can 
remain under water from fifteen to thirty minutes. 
The tables also show that new-born animals born helpless and blind 
resist submersion for a much longer time than adults, a fact known and 
studied by Harvey, 7 Haller, 8 Button, 9 and Legallois, 10 but the duration of 
1 Bernard, quoted from Paul Bert, loc. cit. p. 522. 
2 "De l'mfluence des agens physiques sur la vie," Paris, 1824, pp. 629-632. 
3 Loc. cit. . p. 534. 
4 This article, p. 720. See also " Animal Heat," this Text-hook, vol. i. p. 852. 
5 Loc. cit., p. 550. 
G Burdach, "Traits de physiologie," trad, par Jourdan, tome vi. p. 122. 
7 "De Generatione," Amst., 1651. 8 " Elementa physiologise, " 1761, p. 316. 
9 " Histoire naturelle de l'hoinme." 
10 " (Euvres de Legallois," Paris, 1824, tome i. p. 93. 
