1 6 
Mr. Carlisle's Lecture 
are effected differently from those of high temperature ; in 
some of them, as the amphibia of Linnaeus, the lungs receive 
atmospheric air, which is arbitrarily retained in large cells, and 
not alternately, and frequently changed. The fishes, and the 
testaceous vermes, have lungs which expose their blood to 
water, but whether the water alone, or the atmospheric air 
mingled with it, furnish the changes in the pulmonary blood, 
is not known. 
In most of the genera of insects, the lungs are arborescent 
tubes containing air, which, by these channels, is carried to 
every vascular part of the body. Some of the vermes of the 
simpler construction have no appearance of distinct organs, but 
the respiratory influence is nevertheless essential to their ex- 
istence, and it seems to be effected on the surface of the whole 
body. 
In all the colder animals, the blood contains a smaller pro- 
portion of the red colouring particles than in the mammalia, 
and aves ; the red blood is limited to certain portions of the 
body, and many animals have none of the red particles. 
The following animals were put into separate glass vessels, 
each filled with a pound weight of distilled water, previously 
boiled to expel the air, and the vessels inverted into quicksilver ; 
viz. one gold fish, one frog, two leeches, and one fresh-water 
muscle.* These animals were confined for several days, and 
exposed to the sun in the day time, during the month of 
January, the temperature being from 43° to 48°, but no air 
bubbles were produced in the vessels, nor any sensible dimi- 
nution of the water. The frog died on the third day, the fish 
on the fifth, the leeches on the eighth, and the fresh-water 
* Mytilus Anatinus, 
