148 MANURE. 



The poultry yard is, to a careful farmer, a rich 

 source of vegetable food. How much a single hen 

 can contribute to increase the crops, may be seen 

 from the following account, from Vauquelin. 



214. In ten days a hen ate 7474 grains of oats, 

 which contained of 



Phosphate of lime, 91.8348 grains, 



Silica, 141.8619 * 



During this time two eggs were laid, whose shells, 

 weighed 308*814 grains, 



and contained phosphate of lime, 17*5975 " 

 Carbonate of lime, 276*7095 " 



Gluten, 9-8725 * 



The excrements during the same 



^348*521 



time, gave oi ashes, 



Composed of carbonate of lime, 39*3511 " 

 Phosphate of lime, 184*5348 " 



Silica, 124*6351 " 



Thus voiding in eggs and excrements, 



Carbonate of lime, 315*0606 " 



Phosphate of lime, 202*1323 " 



Now this is 17.2267 grains less silica ; and in 

 round numbers, 1 10 grains of phosphate, and 316 

 grains of carbonate of lime more than the food eat- 

 en contained. Probably in all such experiments, 

 where confined to food different from usual, and de- 



