C 293 
III. On the Elasticity of the Lungs. By James Carson, M. D. 
Communicated by Thomas Young, M. D. For. Sec. R. S. 
Read Nov. 25, 1819. 
In a Treatise which I published a few years ago on the 
motion of the Blood and the mechanism of Respiration, it 
was contended, that a cause essential to the performance of 
these functions, had escaped the notice of physiologists. This 
cause was stated to be the elasticity or resilience of the lungs. 
The resilient property of the substance of the lungs had in- 
deed been admitted by all anatomists and physiologists; and 
it is commonly demonstrated in the lecture room, that, if a 
piece of the substance of the lungs be cut out and stretched, 
it will recover its former dimensions when released from the 
extending power. But though the existence of this property 
had been universally admitted, no physiologist had attempted, 
so far as I know, to explain the means by which nature had 
contrived to render it subservient to the purposes of life. The 
statement and explication of this contrivance, with reference 
at least to certain purposes, constitute in a great measure the 
subject of the treatise to which I have alluded. Although 
it was proved in that Treatise, that, for the performance 
of those movements in which life is acknowledged chiefly 
to consist, a power of considerable extent is derived from 
the elasticity of the lungs, it was at the same time con- 
fessed, that no data had been discovered, from which the full 
