THE STOMACH. 47 



found to rise still higher. Now the gastric juice, from some 

 very ingenious experiments,* is supposed to contain a much 

 stronger principle of life and warmth than other liquids ; thus 

 when water, salt and water, and gastric juice were exposed 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 f 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 Tierra 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 



* Spallanzani. 



t King's Narrative, vol. i. p. 199. 



