A LITTI.K AORK'tTLTURAL CHEMISTRY. 320 



l)uriii{^ ii wurui, dry day Icuvi'S also assuiiu; tliu Hlecjtiii^ i)o- 

 Hitioii, wliicli aids in cht'oking evaporation. 



Tlu'ro an? moro " sleeping " ])lants among the Leguminosie 

 tliaji are found in all (ttlier families jiut together. 



A Little Agricultural <'liLMuistr.v. — Of tlie thirteen elements 

 neeossary for jjlant growth the farmer usually need take hut little 

 <!are, except in tlie sujjply of ])()tassium, ])hos'phorns and nitro- 

 gen, and of these three nitrogen is this mctst precious and costly 

 to ohtain. All agric^ultural plants draw nnudi of tlieir food from 

 the atmosphere, ami of those used hy tlie farmer ])rohahly norm 

 are much, if any, ex(;ee(li'd by clover in the large* jiroporti(»n of 

 nutriment thus derived, in tliis n^spc-ct otlier higuminous crops 

 are much like red (dover. 



''Clover seed is the htist numure tliat a farmer i-au use." 

 Clover has been called " a trap for nitrogen," as it eolhiets and 

 presents large cpuintities of (ioinhined nitrogen in a form ready 

 to nourish growing crops. 



In the words of J)r. Kedzie: "With an adequate sup])ly of 

 combined nitrogen all the other chemicals of agriculture Ijccome 

 active, while u limited supply of active nitrogen correspondingly 

 limits the action of the rest. For high farming, or the raising 

 of exoeptionally large crops, the great want is an alnmdant and 

 cheap supply of ammonia and tlu! nitrates. 



"An acre of good (dover will make 5,000 j)ound.s of hay, con- 

 taining 2Sii\ pounds of mineral nuitter or ash. In this ash will 

 be U7^ })oumls of potash, 00 pounds of lime, lU^ j)ounds of mag- 

 nesia, and 2H pounds of phosphoric acid. The hay will also con- 

 tain 108 pounds of combined nitrogen." 



The roots and stubble contain fully ns much of these elements 



as the hay. 



Sir J. B. Lawes found that in autumn, after tlio last crop 



jf clover was cut, tinit remaining above ground, and to the depth 



of 72 inches was examined: 

 42 



