elasticity of the lungs . 39 
the lungs made to the spring of the contained air, is imputable, 
I think, to their specific gravity. 
On the 16th of September, 1817, the apparatus was ap- 
plied to a calf. When the water in the upright tube had 
reached the height of fourteen inches above its level in the 
globe, the lungs appeared to be distended to the full capacity 
of the chest. Upon cutting off the communication between 
the apparatus and the animal, the water instantly fell to its 
level, and the lungs shrunk into very small dimensions. The 
animal, in this experiment, was placed with the chest erect, 
so that the shrinking of the lungs upwards from the dia- 
phragm to the neck, and which was observed to be as great 
as in any other direction, must have taken place in opposition 
to the specific gravity of the lungs. 
In almost every experiment in which the chest was perfo- 
rated by a sharp instrument, the lungs were found to be 
wounded, and the object in a great measure defeated. In the 
experiment about to be described, and the last which will 
be detailed at this time, great care was taken to prevent the 
accident now mentioned. 
On the 31st of October of the same year, the apparatus 
was applied to the prepared trachea of a dog, which had been 
hanged on the preceding day. Water was poured into the 
apparatus until it stood in the upright tube at the height of 
six inches above its level in the globe. The abdomen of the 
animal was opened, and the diaphragm freely exposed. A 
part of the muscular substance of the diaphragm was drawn 
down in a fold, which was done without difficulty ; and care 
being taken that no part of the lung was contained in the 
