AND AGRICULTURE. 55 



the flame of a lamp, the organic part, or the 

 gelatine, is consumed, and the inorganic part, or 

 the phosphate of lime, remains unburned. The 

 gelatine may be also to a large extent removed 

 by boiling in successive portions of water. By 

 boiling under a pressure of steam, all the gela- 

 tine may be dissolved out. 



The glue or gelatine of bones is a very good 

 and powerful manure ; and materially assists in 

 advancing the growth of the turnip crop. 



The bone-earth, or the part left unconsumed 

 by fire, contains phosphoric acid and lime. The 

 phosphorus and lime are both valuable manures, 

 as may be seen on reference to the table, page 47, 

 which shows how much of these substances some 

 crops annually take from the land. 



Bones are essentially requisite on old dairy 

 lands. Milk and cheese both contain bone-earth ; 

 and, unless the soil is replenished with phosphoric 

 acid and lime, it soon becomes poor and unpro- 

 ductive, or only capable of growing grasses 



Questions. If you burn a bone, what is consumed? 

 What remains unconsumed ? What is the effect of the glue 

 or gelatine of bones ? Of what is bone-earth composed ? 

 Are they valuable manures ? Why are bones requisite on 

 old dairy lands ? 



