THE STOMACH. 
47 
stronger principle of life and warmth than other liquids; 
thus when water, salt and water, and gastric juice were ex- 
posed to great cold, the gastric juice was the last to freeze, 
and the first to thaw. The greater portion of this juice, 
therefore, found in birds, may be an additional means by 
which the wisdom of God furnishes them with more warmth, 
and enables many of them to resist very strong degrees of 
cold. In proof of their endurance of cold, at the bird-market 
of St. Petersburg!!, in Russia, during the intensity of those 
dreadfully cold winters, several thousand cages, containing 
birds of every description, are hung on the outside of about 
eighty shops ; in a part of each cage, a small quantity of snow 
is placed, which is said to be necessary to keep them alive. 
That birds, originally from warm climates, suffer from the 
colder regions of the North, is, to a great degree, true; but by 
far the greatest number of birds, found dead in our severe 
winter, perish not from the inclemency of the weather, but 
the deficiency of food; for instance, our little Wren is just as 
active and cheerful in the severest frost as the warmest 
summer’s day, — his supply of food, consisting of small insects 
concealed under the bark of trees, never failing him. 
As a proof that small birds are not affected so much by 
temperature as want of food, Captain King* observed the 
lesser Redpoll existing without apparent inconvenience in a 
climate, and at a season, when the thermometer was not un- 
frequently at seven degrees below zero; and in the inclement 
atmosphere of Cape Horn, on the desolate shores of Terra 
del Fuego, Humming-birds were constantly seen hovering 
over the blossom of a species of Fuchsia, when the jungle 
composed of this shrub was partially covered with snow. 
There is another singularity in this mysterious liquid, 
namely, the different force with which it acts on the various 
substances used for food by different birds. Thus the gastric 
juice in the stomach of those birds which live on flesh acts 
very sparingly on vegetable substances. On examining the 
castings 4 or pellets of some Eagles, which had been occasion- 
* King’s Narrative, vol. i., p. 199. 
