'Sim 



OMNIS FERET OMNIA TELLUS. VIRC 



Vol.1.] Georgetown, Ca. March 6. [Nr*. 18.] 



On //^e AnaUisis of SoiLf, as connected wit n. t :eir Iitt- 



pmvanent. 7>?/ Humphrey T> avy Esq. F. R. S. 



Froin the Conraiutii.^alions of the Board of Trade- 



Conciudcd iVom pacje 269 



XI il. MoDt: OF DETECTING SuLPSATIC OF LiME 

 (GvPSUIvl) ANJ) PiXOSPMATE OF LiME, IN SoU.S. 



Should sa!phate or phosphate of lime be suspected 

 ill the entire soil, the detection of them requires a parti- 

 c'ular process upon it. A g'iven weight of it. for in- 

 stance four hundred grains, m:ist he h'^ated red for half 

 an hoiK-m a cruciMc, mixed with one-third of powdered 

 chnrcoa!. llie rnixttiFe must be boiled f»r a quarter of 

 ifn honr, in a half pint of water, and the i\\vA eel eeted 

 tP.rGUi;h the tikcr. and exjiosed for some days to t!ic at- 

 I'liosphcrein arj open vessel. If any soh'.ble qviantity of 

 sulphate of Wvac (gypsum) existed in \hc soi?, a white 

 precipitate will g-raduaHy form in theflirid, and t^ie weight 

 ^of it will indicaic tiie proportion. 



Phosphate of lime, if any exis:, may be S'^pa-ated 

 from the so-' after tlie process for gypsnm. Muriatic 

 acid must be digested upon the soil, in quantity more 

 *.han sufficient to saturate the sohible eai'ths ; the sohiti- 

 on must be evaporated, and water poured upon the solid 

 inatier. This fluid will djssolveihe compounds of earths 

 with tljc muriatic acid; and !cavc the phosphate of lime 

 untouched. 



It would not fall within the limits assij^ned to this pa- 

 per to detail any processes for th.e d 'tecnon of >ub^tan- 

 ces which may be aecidenti.lly mixed with tlie matters of 

 soils. Manganese is now and then found in them, and 

 compounds of b;ir'>tic eavtii; but these bodies appeac 



3S 



