1848.] Muvial Soil of the JVile. 143 



a lighter grey than the original soil. Minute particles of white 

 quartz, and some with a reddish tint, are discernible by the help 

 of a lens. 



7. The solution filtered from the above residuum was treated 

 with sulphydric acid, to ascertain whether lead, copper, mercury, 

 tin, antimony, or arsenic, existed in the soil. A reddish white 

 tint, indicative of a bare trace of antimony, was all which could 

 be procured. The liquid smelling strongly of sulphydric acid, 

 the sulphur was separated, and then the solution was neutralized 

 with pure ammonia. 



8. Sulphydrate of ammonia was added, throwing down a copi- 

 ous precipitate of sulphuret of iron and alumina, which was 

 filtered out, redissolved in chlorhydric acid, with a little nitric, 

 and boiled to peroxidize the iron; the solution was then precipi- 

 tated and boiled with pure potash, separating the iron, which be- 

 ing ignited, weighed in the state of peroxide 8.07 grains. 



9. Having acidulated the potash liquid, it was precipitated by 

 ammonia, and gave of ignited alumina 2.64 grains. 



10. The solution, filtered from the sulphurets, was concentrated, 

 treated with chlorhydric acid, the precipitated sulphur separated, 

 and after neutralizing by ammonia, was precipitated with oxalate 

 of ammonia, allowed to repose eighteen hours, then heated and 

 filtered. The oxalate of lime thus obtained, was, after ignition, 

 repeatedly moistened with a solution of carbonate of ammonia, 

 and re-ignited till it ceased to gain weight. The carbonate of 

 lime was 12.6 grains. 



11. Ammonio-phosphate of soda applied to the liquid filtered 

 from the oxalate of lime, after the same had been duly concen- 

 trated, entirely cooled and neutralized by pure ammonia, threw 

 doAvn ammonio-phosphate of magnesia, which, separated and ig- 

 nited, gave of phosphate of magnesia, 5.15 grains, equal to 2.06 

 grains of magnesia, or 4.25 of bi-carbonate. 



From the preceding operations we obtain the following compo- 

 sition of this soil, viz. : 



Per cent 



Water obtained at 212°, .... 4.20 



Organic matter soluble in boiling water, . . 2.30 



Insoluble organic matter, . . . . 2.15 



Peroxide of iron, 8.07 



Alumina, . 2.64 



Carbonic acid, ...... 5.55 



Magnesia, . ..... 2.06 



Lime, . . . , . . .7.11 



Insoluble silicates, ..... 63.55 



Loss, . ...... 2.37 



100. 



