THE STOMACH. 55 



seem to require greater warmth than other animals, 

 since it is found that their blood circulates more 

 rapidly, and is warmer than the blood of the human 

 body. For instance, the heat of the human body 

 will raise the mercury of a thermometer to about 

 95 or 96 degrees, the true blood-heat being 98: 

 but if the same thermometer is placed under the 

 wing of a Parrot, or a Canary, it will raise it to 100 

 or 101; of a Fowl, to JOS; of a Sparrow or Robin, 

 sometimes to 110 or 111; and, no doubt, if tried on 

 certain other birds, requiring additional warmth, it 

 would be 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 at St. Peters- 

 burgh, in Russia, during the intensity of those 

 dreadfully cold winters, several thousand cages, con- 

 taining 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 



* Spallanzani. 



