322 [Dec, 1845. 



caused an additional loss of 3.57 per cent. The powder having now a dull red- 

 dish gray color, was again heated, and with access of air, stirring occasionally 

 with a platinum spatula, to facilitate the complete combustion of organic 

 matter. 



By this treatment the additional loss was .13 grain, showing the organic 

 matter in the soil to be 3.70 per cent. To ascertain what part of ths matter 

 was soluble, a second portion of 100 grains was placed in a green glass matras 

 and boiled for an hour, with three ounces of a saturated solution of carbonate of 

 ammonia ; the clear liquid was decanted, and a second portion of the carbonate 

 added, boiling as before, and in the same way a third portion was subsequently 

 added. The solution being acidulated with acetic acid, acetate of lead was ap- 

 plied, producing when dried, 4.7 grains of crenate of lead, equivalent to 2.28 

 grains of crenic acid, and showing the insoluble organic matter to be 1.42 

 grains. 



3. Placed the reddened powder of the first 100 grains in a matras, and poured 

 over it an ounce of pure water and half an ounce of pure chlorhydric acid ; 

 boiled half an hour, decanted the clear liquid, put in another ounce of water and 

 half ounce of acid, boiled for the same length of time, decanted once more and 

 repeated the operation — then filtered, washed carefully, ignited and weighed the 

 residue, found it 70.2 grains, showing that 22.4 grains of matter have been dis- 

 solved by the acid 



4. Tho solution in chlorhydric acid, reduced to a convenient bulk, was boiled 

 with a little nitric acid, to peroxidize the iron, by which it was changed from 

 greenish yellow to a fine deep red color, and while still hot, precipitated with 

 pure ammonia, boiled to condense the precipitate, filtered, washed for more than 

 24 hours, and until all alkaline reaction ceased. 



5. The precipitate was boiled in a strong solution of caustic potash, until the 

 clear liquid yielded with chlorhydric acid the usual indications of a sufficient 

 excess of alkali. 



6. The remaining precipitate of oxide of iron was filtered and washed for 

 12 hours, with hot water, separated, dried, and ignited sufficiently long to reduce 

 the whole to the state of peroxide, which then weighed 9.18 grains. 



7. The potash solution was acidulated with chlorhydric acid, and precipitated 

 by carbonate of ammonia, yielding, after being thoroughly washed, dried and 

 ignited, 6.55 grains of alumina. 



8. The ammoniacal solution filtered from oxide of iron and alumina, was 

 treated for phosphate of lime, and afterwards with oxalate of ammonia, and, 

 allowing ample time to precipitate, the oxalate of lime was filtered, washed, con- 

 verted into carbonate, and in that stale weighed, giving 6.7 grains. Converted 

 this, by exposure three times to a white heat, into caustic lime, weighing exactly 

 3-8 grains. 



9. The liquid from which oxalate of lime had been filtered, was now with the 

 usual precautions precipitated with ammonio-phosphate of soda, the precipitate 

 cautiously washed, and the double phosphate ignited, giving phosphate of 

 magnesia 5>18 grains, equivalent to 1-89 grains of -magnesia. 



1 0. To the liquid filtered from ammonio-phosphate of magnesia, added sulph. 



