of the Plants of Flax and Hemp, 101 



This composition approaches to that of the azotized animal 

 substances, and surpasses the animal manures usually sold. 

 The water in which hemp has been steeped thus contains most 

 of the nitrogen of the plant, and if poured over the soil should 

 serve efficiently to restore its fertile powers. 



The ashes of the hemp extract require also to be noticed, 

 for the plant, in steeping, gives up to the water especially its 

 soluble constituents. The ashes of the leaves of hemp contain 

 in 22 parts only 1*77 soluble in water, or 8*05 per cent., whilst 

 the ashes of the hemp extract contain in 49*2 parts, 29*70 parts 

 soluble in water, or 60*4 per cent. Thus almost all the alka- 

 line constituents of the ashes are dissolved out by the water, 

 whilst the earthy materials remain associated with the residual 

 portions of the stem. 



Dr. Kane next examined the stem, as it remains after treat- 

 ment for the fibre, by steeping and peeling. Dried at 212° 

 this hemp residue consisted of 



Carbon 56*80 



Hydrogen 6*48 



Nitrogen ..... "43 



Oxygen 34*52 



Ashes 1*77 



100*00 



The ashes contained but a trace of alkali, and it is seen that 

 the nitrogen has almost disappeared. 



From these researches it is plain that, by the quantity of 

 nitrogen, of phosphoric acid, of potash, of magnesia, and of 

 lime, which the hemp takes from the soil, it must be, as ex- 

 perience proves it, a highly exhausting crop ; but as the ma- 

 terials so abstracted are not found in the valuable fibre, but 

 in the residual stem, the chaff, and the steeping liquor, all 

 these are available for the purpose of restoring to the soil what 

 had been taken up, and in fact, if it were possible to carry on 

 the processes of the preparation of the fibre without loss, the 

 same nitrogen and inorganic constituents might, as it would 

 appear from these chemical inquiries and from physiological 

 researches, serve for any number of successive crops of hemp ; 

 the fibre alone, generated at the expense of the atmosphere, 

 being sent out and sold, and thus the crop be absolutely de- 

 prived of all exhausting quality to the soil. 



Dr. Kane's inquiries regarding the flax plant were of a pre- 

 cisely similar character to those described already in the case 

 of hemp, and have led him to similar conclusions affecting the 

 practical culture of this important plant. The general results 

 of his analyses are as follows: — 



