58 



INORGANIC CONSTITUENTS. 



COMPOSITION OF THE ASHEi: OF SEVERAL PLANTS ANALYZED 

 BY M. BERTHIER. 



Fern. 



Wheal 

 straw. 



Observations. 



Sulphate of potash. • • 

 Chloride of potassium 

 Carbonate of potiish. • 

 Silicate of potash . • • • 



Silica 



Carbonate of lime. • . . 



Sulphate of lime 



Phosphate of lime ... 



Macnesia 



Oxide of iron 



Oxide of manganese. • 



0,007 



0,730 

 0,248 



0,010 

 0,005 



0,004 

 0,032 



0,130 

 0,715 

 0,096 



0,023 



The wheat 



itraw was IrDin 

 » strong- calca- 



The wnjjr wm 

 from « raiiily gu- 

 ile n *uil. 



A remark made by Berthicr, and arisinj^ out of the preceding 

 analyses, is the absence of ahimina in the constituent princi])b^s of 

 the ashes examined. The results previously obtained bv M. de 

 Saussure fully confirm this remark ; and if in some cases traces of 

 alumina were detected, the circumstance was attributed to the clay 

 which might accidentally have adhered to the plants. Accordinji: to 

 M. Berthier the absence of alumina is probably owinfj lo its insolu- 

 bility in water, and its weak affinity for the organic acids. The solu- 

 ble salts of alumina with mineral acids are, it is well known, unfa- 

 vorable to vegetation, and in an arable soil they could not exist along 

 with calcareous or alkaline carbonates : they would be immediately 

 decomposed. 



However, alumina appears actually to have been observed in the 

 slate of salt in the juices of certain plants : hjcopodium cornplanatum, 

 an infusion of which is employed as a mordant in dyeing, contains 

 tartrate of alumina ;* the same salt has been detected in verjuice ; and 

 as we shall see presently, ^'autjuelin found acetate of alumina in the 

 sap of the birch-tree. 1 may add, that in a considerable numbi-r of 

 analyses of ashes, produced from j)lants and seeds of my own grow- 

 ing, I always obtained traces of alumina : but I would not venture 

 to atfirm that the earth here was not accidental. 



Silica is met with in oidy very small quaniily in the ashes of wood. 

 It is found, on the contrary, in con.siderable proportion in the ashes 

 of several annual and biennial plants, anil more especially in those 

 of the cereals. Sir Humphrey Davy found silica in the epidermis 

 of the Indian rush. 



If we compare the ashes of the same species of wood grown in 

 soils of diflerent kinds, we see, says M. Berthier, that tliey may dif- 

 fer very perceptibly; which seems to establish the fact tliat the soil 

 exercises a certain degree of inlluence on their constitution. Thus 

 oak-wood from Hoque des Arcs, grown in a decidedly calcareous 

 soil, yielded ashes almost entirely consisting of carbonate of lune, 



• Bcrzeliu^, Traits de ChintU. I. '. p. 130, Fr»nch trariilation. 



