38 
Dr. Carson on the 
preceding instances, till it stood sixteen inches above the level 
of the water in the globe. An opening was then made into 
the abdomen. A fold of the fleshy part of the diaphragm 
was then drawn down on each side, and care being taken that 
no part of the lung was included in the fold, it was cut into. 
The sound of a current of air pressing through the openings 
into the chest was distinctly heard, and the water in the up- 
right tube arose instantly to the height of eighteen inches 
above the level of the water in the globe. The diaphragm, 
before the openings, was still tense, and slightly concave to- 
wards the belly ; but after that it became lax, wrinkled and 
flat. Some additional water was poured into the apparatus ; 
but we were prevented in this case, as in the preceding, 
from ascertaining the amount of the force requisite to distend 
the lungs to the dimensions which they usually occupy 
in the living animal, by the deficient capacity of the glass 
globe. 
By these experiments, I think it is clearly ascertained, that 
the spring of air compressed by a column of water of a foot 
and a half high, is not equal to the resilience of the lungs of 
an ox, at the usual stage of their dilatation. 
In all these experiments, the oxen were placed upon the 
back with the shoulder raised a little above the rest of the 
body : some share of the collapsing effort of the lungs might 
be imputed to their specific gravity. But when the levity of 
the lungs is considered, and also that they were observed not 
to shrink more from the breast to the spine than from the 
diaphragm to the neck, in opposition in this case to gravity, 
and that their dimensions were not increased, nor their form 
varied by any change of position ; little of the resistance which 
