of Organic Bodies. 179 



The composition in 100 parts was as follows: — 



Seed. Straw. 



Potash 30-45 



Soda 4-48 



Carbonate of lime 63*38 



Carbonate of magnesia . ... 20*46 



Lime 8*06 4*45 



Magnesia 14*34 046 



Peroxide of iron . . 1*36 2*13 



Phosphoric acid . . . 40*63 5*93 

 Sulphuric acid . . . 0*32 



Silica 0*36 3-19 



100*00 100*00 

 The composition of the phosphates precipitated by am- 

 monia from the muriatic solution was as follows, after havmg 

 been heated to redness :— 8CaO + Pg O5+ 2MgO + P2 O5 

 + 2Fe2 03 + 3P2 O5. The calculated quantity of phosphoric 

 acid in this precipitate amounts to 34*24 per cent. ; analysis 

 yielded 34*47 per cent. Thus there is an excess of 6*16 per 

 cent, phosphoric acid. 



The phosphates precipitated by ammonia from the acid 

 extract of the straw consisted, after having been heated to 

 redness, of 2CaO, Pg O5 + 2MgO, P2 O5 + Fcg O3. 



T^e remaining carbonaceous mass. — The ash it contained 

 consisted of — 



Seed. Straw. 



Potash 21-50 



Soda 0*29 



Lime 15*19 27*53 



Magnesia 14*08 13*51 



Peroxide of iron . . . 0*46 4*20 



Phosphoric acid . . . 45*79 9*29 



Sulphuric acid . . . 1*87 

 Silica 0*82 45*47 



100-00 100*00 

 The composition of the phosphates precipitated by am- 

 monia from the acid solution of the ash of the seeds was 

 2CaO, P2O5 + 2MgO, P2O5+ Fe203, 3P2 O5. The phosphoric 

 acid required by calculation is 44*17 per cent.; that found by 

 experiment amounted to 44-10 per cent. Hence there is an 

 excess of 1-69 per cent, phosphoric acid, which existed in the 

 liquid filtered from the earthy phosphates. Ammonia how- 

 ever produced only a very slight precipitate in the acid solu- 

 tion of the ash of the carbonized straw ; the fluid filtered from 

 this still contained lime and magnesia. 



N2 



