AGRICULTURAL MUSEUM g7$ 



ifi (Ills instance the loss is supposed pma'l; ^ut in ge- 

 neral, in acUial experiments, it will be fo'md murh great- 

 ev, in conseq Tence o*' the difiiculty of collecting the 

 wliole quantities of the d'iierent pp'cinitates ; and uh -n 

 it is within thirty f<.r four hundred grains, these is no 

 reason to suspect any want of due piecision in tlie 

 processes. 



XV". This GE?fERA.L IMetiiod of Analysis may 



IN MANY Cases be. much simplified. 



When the experimenter is become acquainted witii 

 ihe use of the (li!r''rcnt instriim-'uts. the properties of 

 the re-agents, and the r^-lations bctw -en the external 

 and chjmical qualities of soils, he will seldom tindifc 

 necessary to perfoiu, in any one case, all (he processes 

 that have been described. When his soil, for instance, 

 contains no notable proportion of calcareous matter, 

 the action of tlic fnurialie aeicf |X. may he omitted. In 

 examining peat soils he will principally have to attend 

 to the operation by Hre and air X. ; and, in the analysis 

 of chaK s and loanis, he will often be ubie to omit the 

 experiment by sulphuric acid XL 



In the first trials that are m:iue by persons unac- 

 quainted with chymistr}', they must not expect much 

 precision of result. Many diaieulties will be met with; 

 but in overcomina^ them, the most usefu! kind of pi-ac- 

 tical knowledge will be obtained ; and nothing is so 

 instructive in Gxperinsental science, as the detection of 

 mlstakf^s. The correct analyst onahtto be well groiinded 

 in chymieal genera! information ; but pci ha, s there is 

 no !)etler mode of gaining it than that of attcmj.'ting ori- 

 ginal investigations. In pursuing his experiments, he 

 will be continually obliged to learn from b;>oks. the 

 history of the substances he is employing or acting 

 upon ; and his t! c:>ret':cal ideas vy 11 he moi-e va!ii-»b'e in 

 Lei ig eon It cted with practical operation;, and acquired 

 for tac purpose of discovery. 



