Essay on the Analysis of Soils. 



55 



tience^ if we would come to a very accurate result. Every por- 

 tion must be dried to the same degree before it is weighed j — 

 minute portions which adhere to the vessels, when dried, must be 

 carefully collected by scraping, and brushing off with a feather ; — 

 pieces of filtering-paper and of linen must be weighed before they 

 are used, that small portions of matter adhering to them may be 

 ascertained by the increase of weight. By attending to these par- 

 ticulars it is surprising how nearly the whole original weight is 

 accounted for in the summing up of the separate parts. 



If this mechanical analysis should be thought lightly of by ex- 

 perienced chemists, let them only carefully analyse a portion of 

 soil by this process, and then another by any more perfect mode, 

 and compare the importance of the results, as regards practical 

 agriculture. The object is to ascertain the productive powers of 

 the soils ; and, for this purpose, the separation of the different 

 earths is sufficient, in the present imperfect state of our knowledge 

 of the mysteries of vegetation. 



The process which we hav-e described, simple as it is, may yet 

 be too tedious for the farmer who is desirous of speedily com- 

 paring different soils ; and we will indicate a still simpler method 

 of ascertaining, nearly, the composition of a soil^ and a simple 

 instrument by which it may be done. Take a glass tube, f of 

 an inch in internal diameter, and 3 feet long ; fit a cork into one 

 end, and set it upright ; fill it half- full of pure water ; take nearly 

 as much water as has been poured into the tube, and mix with, 

 it the portion of soil which is to be examined, in quantity not 

 more than will occupy 6 inches of the tube ; pour the mixture 

 rapidly into the tube, and let it stand in a corner of a room, or sup- 

 ported upright in any way. In half-an-hour it may be examined. 

 The earths will have been deposited according to the size and 

 sj^ecific gravity of their particles. The portion still suspended in 

 the water may be allowed to settle ; and there will appear in the 

 tube layers of sand, clay, and humus, which may be measured by a 

 scale, and thus the proportions nearly ascertained. When a farmer 

 is about to hire a farm, of which the quality is not well known to 

 him, he may be much assisted in his judgment by this simple 

 experiment, if he has no time or opportunity for a more accurate 

 analysis. For the glass tube may be substituted one of tin or zmc, 

 2 feet in length, with a piece of glass tube, a foot long, joined to 

 it by means of a brass collar or ferule with a screw cut in it, which 

 is cemented to the glass, and screws on the metal tube ; and thus 

 the instrument may be made more portable. When the water has 

 been pOured off, and the earths only remain, the cork may be 

 taken out, and the contents pushed out on a plate, by means of a 

 rod and a plug which exactly fits the internal diameter of the 

 tube. They may thus be more particularly examined. 



