88 RECAPITULATION. 



portionally greater in the leaf and head, than in the stem. There is less than one- 

 third I'f dry matter in the stalk. Hay, in making or drying in the sun, loses more 

 than one-half its weight in water- Sun-dried hay loses about 12 per centum, when 

 exposed to 212° in a water bath. It docs not differ materially in this respect from 

 the straw of grains. 



4. In a ton of dry hay, about 150 lbs. of silica, phosphates and potash, are removed from 



the soil. So if two tons are yielded per acre, 300 lbs. of these important substances 

 are taken off. From this fact, it is evident that but few soils can produce an abundant 

 harvest, unless the removed matter is returned in some form. 



5. For a crop of hay, it is well determined what manures are required. In treating a 



field for grass, however, we may furnish manures indirectly ; that is, apply those 

 matters which will unlock the potash from its combination with silica. This is often 

 effected by the use of hydrate of lime. Immediate results follow from the application 

 of ashes, leached or unleached. 



6. Sulphur is another element which is always present in hay : it may be in combination 



with lime or other alkaline earths, or in its simple state in the albuminous matters. 



7. An interesting fact is brought out by the examination of the constituents of grasses at 



different periods ; thus in the Triticum repens, the inorganic matter decreases with the 

 age, while the organic matter increases. 



The coarse grasses of swamps, and those usually known as aquatics, contain large 

 quantities of water, while the inorganic part or ash is quite small. They do not seem 

 to be valuable for cattle, and but few arc eaten. Some, however, which are early, 

 are sought after ; and then again some of the later grasses of a coarse texture are 

 eaten, as the cocksfoot grass, which continues green till frost. The most important 

 use to which the coarser grasses can be applied is for litter ; for which purpose, they 

 may be placed in stables or yards, where, from the absorbent nature of their stems, 

 they will necessarily take up the urine and other moist manures with which they 

 come in contact. 



8. It will be observed that clovers differ essentially in composition from the grasses : they 



are strictly lime and potash plants. Phosphoric acid is also equal in importance to 

 any of the other elements. The silica amounts scarcely to one per centum. 



9. When clover is removed from a field, and no returns are made, it is evident that it 



exhausts a soil quite as much as timothy. Thus 123 lbs. of inorganic matter are re- 

 moved in a ton of clover hay, which consists mainly of expensive elements, viz. 

 phosphoric acid, lime and potash, amounting in those three substances to 100 lbs. 



10. It is also evident that we may apply tlie proper manures for clover. Gypsum is well 

 known for this purpose ; and the large quantity of lime which the plant yields on 

 analysis, seems to indicate that gypsum is taken up immediately by the roots. 



The use of clover to the wheat crop is indicated in the composition of its ash. Be- 

 sides acting mechanically in loosening the soil, it also furnishes the elements which 

 the wheat plant requires ; and it is probable, from the quantity of water in the stems 



