152 THE POULTRY-BOOK. 



even gone so far as to assert that these substances contributed 

 directly to nutrition. Reor, an Italian physician, made exper- 

 iments by which this notion is entirely exploded. He shut up 

 two capons, with nothing but water and small pebbles for food, 

 and found that they drank much water, but died, one in 

 twenty, the other in twenty-four days, neither of them hav- 

 ing swallowed a single stone. 



In the light of these experiments, the question of the use 

 and effects of the swallowing of pebbles by poultry seems to 

 be decided. It is certain that they are not at all necessary to 

 the trituration of the hardest kinds of substances which can be 

 introduced into the stomach ; and, of course, the usual food of 

 fowls can be sufficiently bruised without their aid. It is not 

 to be denied, however, that they serve a useful auxiliary pur- 

 pose. When put in motion by the muscles, they are capa- 

 ble of producing some effects on the contents of the stomach, 

 and thus assisting to grind down the grain, and separating its 

 parts, the digestive fluid, or gastric juice, comes more readily 

 in contact with it. 



It seems that fowls have some power of retaining the stones 

 taken into the gizzard, and of evacuating them when they 

 become smooth ; but they are never known to disgorge them, 

 as birds of prey throw off what they cannot digest. Some- 

 times, also, they swallow too great quantities ; and instances 

 are cited by some writers, in which the whole cavity of the 

 gizzard has been filled with gravel. Disease and death, in 

 such cases, are likely to supervene. 



VARIETIES OF FOOD. 



Fowls about a poultry-yard can usually pick up a portion 

 of their subsistence, and, under favorable circumstances, the 

 largest portion ; and in such situations, poultry-keeping decid- 



