Ashes of the Flax Plant. 109 



and that whilst the mineral elements of these are what the 

 value really consists in, the value of the flax is altogether in- 

 dependent of those constituents, which are thus so much real 

 loss to the farmer. 



Hence, under the ordinary plan of cultivation, farmers were 

 certainly in the right to consider it one of the most exhausting 

 crops ; and that its place in rotation should be equivalent to 

 that of a grain crop, which it ought by no means to follow, or 

 be followed by ; whereas, under a system of management which 

 should allow of the proper oeconomy of its mineral constituents, 

 that are separated in the processes of watering and dress- 

 ing, the phosphoric acid and other materials might be restored 

 to the manure heap or to the field, and the crop of flax be 

 thus deprived of those permanently exhausting qualities which 

 it now possesses. 



It will be interesting further to notice the constitution of 

 these ashes, under a point of view which has been put forward 

 by some chemists, as possessing the character of a general rule 

 or law; to wit, that although the individual bases present in 

 an ash may vary very much, and even some (as in one of the 

 ashes analysed, B soda) may be totally absent, yet the sum of 

 the oxygen present in the bases will be found to be constant. 

 If we apply that rule to the ashes above analysed, we shall 

 find — 



Title of ash. Quantity of oxygen in bases. 



A 13-73 



B 10-95 



C 14-65 



D 13-45 



H 13-60 



Average . 13*28 



There is certainly a close agreement among these numbers; 

 and if we excluded one analysis (B), which is also exceptional 

 in containing no soda, it should decidedly appear that the 

 quantity of oxygen present in the bases of 100 parts of ash 

 was represented by a constant number (13*86). It will be 

 found that the analyses of Irish flax lend support to this view; 

 but I think that we shall require very many more analyses 

 before we can fix upon it as a positive law. 



In order to afford comparison with the results above given, 

 I have extended my analyses of Irish flax ; and as there appear 

 one or two remarkable points of difference between them, I 

 shall notice also my prior results. 



The flax I originally experimented on was grown at my 

 own residence, a short distance from Dublin. It yielded, 



