Prof. H. Rose on the Inorganic Constituents 



to' 



ganic constituents of peas and pea-straw, which is more fully 

 described in the appended supplement (I. and II.). They 

 were both carbonized, with exclusion of the air, at such a 

 temperature, that the water with which the carbonized mass 

 was treated was not coloured yellow or brown, but re- 

 mained perfectly colourless. Water extracted from the car- 

 bonized mass of the peas a large amount of chloride of po- 

 tassium and phosphate of potash, some chloride of sodium and 

 sulphate of potash, and a considerable quantity of carbonate 

 of potash : the latter must have been contained in the peas, 

 before carbonization, in the form of the potash-salt of an 

 organic acid. Water extracted from the carbonized mass of 

 the pea-straw a far larger amount of carbonate of potash, but 

 smaller quantities of chloride of potassium, chloride of sodium, 

 sulphate of potash, silicate of potash, and sulphate of lime. 



When the carbonized mass, which had been exhausted 

 ■with water, was then treated with muriatic acid, the latter 

 dissolved out of the carbonized peas phosphate of soda, pot- 

 ash, lime, magnesia, and perphosphate of iron, but no earthy 

 carbonates; whilst from the carbonized pea-straw this acid 

 extracted a large quantity of carbonate of lime, a small quan- 

 tity of carbonate of magnesia, and the phosphates of lime, 

 magnesia and iron, but none of potash or soda. 



The carbonized mass which had been exhausted with water 

 and muriatic acid was burnt with access of air. The ash of 

 the peas consisted of the phosphates of potash, lime, mag- 

 nesia and iron ; that of the pea-straw was composed of the 

 phosphates of magnesia, lime and iron; it contained no pot- 

 ash, but a considerable quantity of silica. 



On comparing the amounts of inorganic matters obtained 

 from the peas and the pea-straw by these two operations, the 

 following results are obtained. 100 grms. of peas and 100 

 grms. of pea-straw yielded — 



Peas. Pea-straw. 



Exhausted by water 0*380 r417grm. 



Exhausted by muriatic acid . . . 0*356 3*4<58 grms. 

 On the incineration of the car-"] « ^«« r.a^,- 



bonizedmass J 0*909 0*375 grm. 



Hence water and muriatic acid dissolved very considerable 

 quantities of inorganic constituents from the carbonized pea- 

 straw, but not more than a sixth or seventh of this amount 

 from the peas; whilst on the incineration of the carbonized 

 mass which had been exhausted by solvents, far more fixed 

 salts were formed in the case of the peas than in that of the 

 pea-straw. 



The proportion in the latter case is, however, far more 



