204 BULLETIN OF THE BUSSEY INSTITUTION. 
Matters insoluble in 
chlorhydric acid = 29.00 
100.68 
Or altogether: — ' 
Potash © 10 10 0 ye fe) ana 
together L174} Ne aL 
Soda ervey sl 
Chloride.of sodium... 65! see ie 8 
Lime.) Be ke fade eae cw ae ce. en 
Magnesia .. ‘ she Ee eee 
Carbonates of bins bude magnesia iiddolyeai By ata iat ee 
Oxide offiron’ . 3)... diet ee eS Le 
Aluminait. 2.000 ee) ce Bil es pe Ye be Ge bs ig 
Phosphoric’acid ©. ).0 2 they. ee ue 8 Le Or 
Sulphuniciacia wf 2.5, 0 0 Ol ge et ee 
Silica and organic matter Riayolved Re na. ee 0.36 
Carbonic atid .G.Gite6 . Weilhe 6 cet ok cco ae yee | 29. 67 . 
Garton! a ifae wid ee ew te ee 
Matters sieplabied in an Ue oe ne oe ce aie rrr 
100.68 
It is plain from my own results, as well as from those of Professor 
Johnson and of Stein, that the fertilizing action even of leached ashes 
cannot any longer be specially attributed to the phosphates that are 
contained in them. No doubt the small proportion of phosphates 
actually present is useful, so far as it goes, but so is the potash also; 
and in a fertilizer so poor as leached ashes are, in respect to the more 
important elements of plant-food, the lime and magnesia compounds 
undoubtedly have considerable significance. | 
The idea which has been accepted and promulgated by many writers 
upon agricultural chemistry, that leached ashes are rich in phosphates, 
appears to have been based upon some of Berthier’s* analyses of the © 
insoluble part of several kinds of wood-ashes that had been carefully 
prepared by him in the laboratory, and upon the general inference, 
drawn from numerous other analyses of laboratory products, such as 
are reported in the table on page 207, that, if fresh ashes contain 5% 
or so of phosphoric acid, the insoluble matter in those ashes which 
usually amounts to some 85 or 90 parts, and in which almost the 
whole of the phosphoric acid would naturally be retained, must be 
credited with as much as 5} or 6% of it.. Certain rough analyses of 
leached ashes, such as are used as manure in the south of France, 
* “ Annales de Chimie et de Physique,” 1826, 32. 248. 
