on the Action of the Heart, &c. 451 
the circulation could not be maintained ; and if the circula- 
tion ceased, the cooling properties of the air must be more con- 
fined to the thorax, and not communicated in an equal degree 
to the more distant parts. The following experiment, how- 
ever, was instituted, as likely to afford a nearer approxima- 
tion to the truth, than any other that could be devised. 
Experiment 8.—I procured two rabbits of the same size 
and colour: the*temperature of the room was 64°. I killed 
one of them by dividing the spinal marrow, and immediately, 
having made an opening into the left side of the thorax, I 
tied a ligature round the base of the heart, so as to stop 
the circulation. The wound in the skin was closed bya 
suture. An opening was then made into the trachea; and 
the apparatus for artificial respiration being fitted into it, 
the lungs were inflated, and then allowed to collapse as in 
the former experiment, about 36 times ina minute. This 
was continued for an hour and a half, and the temperature 
was examined at different periods. The temperature of the 
room being the same, I killed the second rabbit in the same 
manner, and measured the temperature at corresponding 
periods. The comparative. temperature of the two dead 
animals, under these circumstances, will be seen in the fol- 
Jowing table. 
4 
Dead Rabbit whose lungs | Dead Rabbit whose lungs 
were inflated. were not inflated. 
Time. (alg ak ie GE eC Terre Te 
\Therm. in thelTherm. in the/ Therm. in the|/Therm. in the 
| Rectum. Thorax. Rectum. Thorax. 
Before the 
Stesesririciin | ee tO 1oe 
30 min. 97 98 
cea 954 96 
60 — g4 g44 
TD = 925 93 
90 — gi 86 got 881 
up wh ope <i ary mumpe elieg ve hela 
In this last experiment, as may be seen from the above 
table, the difference in the temperature of the two rabbits, 
at the end of an hour and a half, in the rectum, was half a 
degree, aud in the thorax two degrees anda half; whereas, 
4n the preceding experiment, at the end of an hour and forty 
minutes, the difference in the rectum was 2} degrees, and 
in the thorax 3 degrees. It appears, therefore, that the rab- 
bit in which the circulation was maintained by artifical re- 
F fe spiration, 
