1 72 Prof. H. Rose on the Inorganic Constituents 



i 98-93 



Thus the chlorides exist in the aqueous extract of the car- 

 bonized peas in far larjrer quantity than in that of the pea- 

 straw. Phosphoric acid exists only in the peas; it is entirely 

 absent from the aqueous extract of the carbonized pea-straw ; 

 whilst the latter contains a much larger quantity of carbonate 

 of potash than the carbonized peas, so that the evaporated 

 aqueous extract of the carbonized pea-straw would have exactly 

 the same composition as several of the commercial kinds of 

 potash. 



The aqueous extract of both the carbonized peas and the 

 pea-straw contained some, although not a large quantity, of 

 free potash, formed by the above-mentioned action of the car- 

 bon upon carbonate of potash. As we have already stated, 

 the conversion of the potash into the carbonate by the trans- 

 mission of carbonic acid through the solution was omitted in 

 all the analyses. Hence it is calculated as potash in the eva- 

 porated aqueous extract. 



Muriatic extract. — The carbonized peas after exhaustion 

 with water did not evolve carbonic acid when treated with 

 muriatic acid ; the carbonized straw, however, effervesced 

 strongly, and hence contained a large quantity of earthy car- 

 bonates. As the amount of carbonic acid could not be deter- 

 mined directly, the lime and magnesia not precipitated from 

 the muriatic solution by ammonia in the form of earthy phos- 

 phates are calculated as carbonates. 



The composition of the constituents in the two extracts was 



as follows : — 



Peas. Pea-straw. 



Potash 54-63 



Soda 7-56 



Carbonate of lime 60*19 



Carbonate of magnesia . ... 5*26 



Lime 8-22 6-92 



Magnesia 6*52 5-69 



Peroxide of iron . . . 1*33 I'lS 



Phosphoric acid . . . 20-79 18-29 



Silica 0-95 2-52 



100-00 100-00 



