EXPEIUMENTS ON CLOVEK. 143 



with difficulty be excavated to a depth of six inches, when the bare 

 limestone-rock made its appearance. At the bottom of the field 

 the soil was much deeper, and the clover stronger,.than at the upper 

 part. On the brow of the hill, where the clover appeared to be 

 strong, a square yard was measured out ; and at a little dhtmce off, 

 where the clover was very bad, a second square yard was meas- 

 ured; in both plots, the soil being taken up to a depth of six 

 inches. The soil, where the clover was good, may be distinguished 

 from the other, by being marked as No. 1, and that where it was 

 bail, as Xo. 2. 



CLOVER-SOIL NO. }. (GOOD CLOVER). 



" The roots having first been shaken out to free them as much 

 as possible from the soil, were then washed once or twice with cold 

 distilled water, and, after having been dried for a little while in the 

 sun, were weighed, when the square yard produced 1 Ib. 10 oz. 

 of cleaned clover-roots, in an air-dry state; an acre of land, or 

 4,840 square yards, accordingly yielded, in a depth of six inches, 

 3.44 tons, or 3 tons in round numbers, of clover-roots. 



" Fully dried in a water-bath, the roots wero found to contain 

 altogether 44.67 per cent of water, and on being burnt in a pla- 

 tinum capsule, yielded G.089 of ash. A portion of the dried, finely 

 powdered and well mixed roots, was burned with soda lime, in a 

 combustion tube, and the nitrogen contained in the roots other- 

 wise determined in the usual way. Accordingly, the following 

 is the general composition of the roots from the soil No. 1 : 



Water 44.C75 



Organic matter* 49.236 



Mineral matter 6.089 



Jmcco 



* Containing nitrogen 1.297 



Equal to ammonia 1.575 



u Assuming the whole field to have produced 3 tons of clover- 

 roots, per acre, there will be 99.636 Ibs., or in round numbers, 100 

 Ibs. of nitrogen in the clover-roots from one acre ; or, about twice 

 as much nitrogen as is present in the average produce of an acre 

 of wheat." 



" That is a remarkable fact," said the Deacon, "as I understand 

 nitrogen is the great thing needed by wheat, and yet the roots alone 

 of the clover, contain twice as much nitrogen as an average crop 

 of wheat. Go on Charley, it is quite interesting." 



"The soil," continues Dr. Vcelcker, "which had been separated 

 from the roots, was passed through a sieve to deprive it of any 

 stones it might contain. It was then partially dried, and the nitro- 



