724 
C HEM 1ST R Y OF RESPIRATION. 
\ 
Condition of Frog. 
Oxygen per 
Kilo, and Hour. 
Carbon Dioxide 
per Kilo. 
and Hour. 
COa 
o 2 
Temperature. Remarks. 
Normal 
After removal of 
lungs 
Gnns. 
fMin. 0-063 
[Max. 0-105 
i 0-047 
[ 0-066 
Grms. 
0-045 
0-081 
0-049 
0-071 
•69 
•78 
•76 
•79 
15 -9 J ) Result of 
> five experi- 
,, \ ments. 
17° 
21° 
Berg, 1 on the other hand, found the discharge of carbon dioxide considerably 
diminished, but this has not been confirmed by Fubini, 2 who observed, in 
comparative experiments, only a slight decrease in the output of carbon 
dioxide after removal of the lungs. 
To all of these experiments there are certain objections. The varnish, 
especially when containing alcohol, acts injuriously on the frog, and interferes 
with its free movement ; the removal of the lungs, apart from the actual injury 
done to the animal during the operation, may cause the skin to take on 
vicariously the function of respiration. Later experiments by King 3 are free 
from these objections, for the head of a normal frog was passed through a 
rubber collar into one part of a chamber, while the body was retained in the 
other part — the pulmonary and cutaneous respiration were thus determined 
separately; and in order to allow for the cutaneous respiration which would 
take place on the head, other experiments were made, in which only the nose 
projected, and in which section of the vagi nerves, an operation which suspends 
the pulmonary respiration, had been performed. The results show that, during 
the winter at least, the cutaneous respiration is far more important than the 
pulmonary. 
c 
1 
3 
p. 
Dura- 
tion of 
Experi- 
ment. 
Weight 
of 
Frog. 
Sex. 
I.— CO2 per 
100 Grms. and 
24 Hours. 
Head and 
Lungs. 
II.— C0 2 per 
100 Grms. and 
24 Hours. 
Body below 
Head. 
Ratio 
of 
I. to II. 
Remarks. 
1 
Hours. 
3 
Grms. 
77 
Male 
Grms. 
•0581 
firms. 
•1891 
1-3-2 
Normal. 
3 
i, 
111 
,, 
•0540 
•1902 
1-3-5 
! ) 
•8 
" 
82 
Female 
•0536 
•2361 
1-4-4 
Only the nose pro- 
jected through the 
partition. 
9 
s j 
177 
•0175 
•0786 
1-4-4 
Both vagi eut ; 
membrane as in 
Experiment 8. 
Dissard 4 has determined the production of carbon dioxide after ligature of 
the cutaneous or the pulmonary blood vessels of frogs, and he finds that both 
cutaneous and pulmonary respiration are necessary to the animal, for the 
1 "Untersuch. ueber d. Hautathmung d. Frosches," Diss., Dorpat, 1868. 
2 Untersuch. z. Katurl. d. Mensch. u. d. Tliicre, 1878, Bd. xii. S. 100. 
s Arch,f. Physiol., Leipzig, 1S84, S. 183. 
4 Compt. rend. Acad. d. sc, Paris, 1893, tome cxvi. p. 1153. 
