NOT AN EXHAUSTING CROP. 311. 



the farm. The fibre thus removed, including the tow and 

 pluckings, never exceeds 10 per cent, on the original 

 weight of straw, and according to some experiments made 

 some six or eight years ago by Dr. Hodges, for the purpose 

 of ascertaining the relative proportions of the produce of 

 flax, and also of the distribution of the inorganic matter 

 in them, carries away with it but a very small portion of 

 the mineral substances abstracted by the growing crop from 

 the land. The flax experimented upon by Dr. Hodges had 

 been steeped in the ordinary way, and was found to con- 

 tain 173 of ash. Of this undried steeped straw 4000 Ibs. 

 weight was taken, which produced 



Of dressed fibre 500 Ibs. 



Fine tow 132 J 



Coarse tow 192 



824- Ibs. of fibre altogether. 



These several products were duly examined and found to 

 contain 



In the dressed fibre 4'48 Ibs. of ash. 



Fine tow 2'08 



Coarse tow 256 



Or, in the whole 824 Ibs. of the fibre, 9'12 Ibs. of inorganic matter ; 



so that of the 69*20 Ibs. which were contained in the 4000 

 Ibs. weight of steeped straw operated upon, only 9*12 ]bs. 

 were carried off in the market fibre, the rest being left 

 on the ground in the refuse portion of the crop. Now, as 

 the straw generally loses about two-fifths of its original 

 weight by steeping, these data of Dr. Hodges would 

 show that if the fibre only were sold off the farm, the 

 quantity produced from a crop of flax yielding 2 tons of 

 straw to the acre would not take with it more than about 

 5 Ibs. of inorganic or mineral matter, a quantity too 

 small to exert any appreciable effect, for good or for bad, 

 upon the fertility of any soil. 



The extraction of the oil, resulting in the manufacture 

 of linseed or oil-cake, and the large and increasing con- 



