40 
Dr. Carson on the 
fold, an incision was made into it. This was done on both 
sides. The water ascended instantly about an inch in the 
upright tube, and the lungs were found to have receded from 
the openings. Water was poured into the apparatus, until 
its level in the tube stood above that in the globe at the height 
of ten inches. The openings in the diaphragm were care- 
fully extended along the chest, and the lungs exposed freely 
to view. They were now apparently dilated to the boun- 
daries of the chest. In this experiment, the water in the tube 
remained steadily at the same height, and the lungs continued 
fully dilated. In those experiments in which the water was 
observed to descend slowdy, and the lungs to collapse gra- 
dually, it is very evident, that the lungs must have been 
wounded, so as to allow some air to escape through the 
pleura. 
The appearance which the lungs exhibited in this situation 
was nov 1 and interesting, and was no doubt the same which 
they would have exhibited in the living body, had it been 
possible to bring them into vievV. Their surface was smooth 
and polished, and their edges rounded, without any of those 
corrugations and sharp angles which they usually exhibit. 
Their colour was red, and life-like. They felt firm to the 
touch. The heart appeared like a bird nearly covered by its 
nest. 
The state of the diaphragm in this experiment was worthy 
of remark. Before the incisions were made into it, it still 
exhibited a degree of concavity towards the belly, but not 
with the same degree of tenseness which it is generally 
observed to possess ; for a fold of it was taken with ease,, 
