ANALYSIS. 



ANALYSIS. 



ascertain the productive powers of the soils ; 

 and for this purpose the separation of the dif- 

 ferent earths is sufficient, in the present im- 

 perfect state of our knowledge of the mysteries 

 of vegetation. The process which we have 

 described, simple as it is, may yet be too te- 

 dious for the farmer who is desirous of speedily 

 comparing different soils; and we will indicate 

 a still simpler method of ascertaining, neauy, 

 the composition of a soil, and a simple instru- 

 ment by which it may be done. Take a glass 

 tube, ^ths of an inch in diameter, and three 

 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 supported 

 upright in any way ; in half an hour it may 

 be examined. The earths will have been de- 

 posited according to the size and specific gra- 

 vity of their particles. The portion still sus- 

 pended in the water may be allowed to settle ; 

 and there will appear in the tube layers of 

 sand, clay, and humus, which may be mea- 

 sured by a scale, and thus the proportion 

 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 zinc two 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 instru- 

 ment may be made more portable. When the 

 \vater 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 inter- 

 nal diameter of the tube. They may thus be 

 more particularly examined. The result of 

 various accurate analyses of soils shows that 

 the most fertile are composed of nearly equal 

 quantities of silicious and argillaceous earths 

 in various states of division, and a certain 

 proportion of calcareous earth, and of humus 

 in that state in which it attracts oxygen and 

 becomes soluble, giving out at the same time 

 some carbonic acid. No chemist has yet been 

 able to imitate the process of nature in the 

 formation of this substance ; and the circum- 

 stances which are most favourable to it are 

 not yet fully ascertained. Here is the proper 

 field for the application of science and accu- 

 rate chemical analysis. As an example of an 

 analysis will be useful to those who may ae- 

 sire 'to try the proposed method, we will add 

 one actuallj r made under very unfavourable 

 circumstances, and without any apparatus ; 

 the only instrument at hand were scales and 

 weights of tolerable accuracy, three glasses a 

 foot long, and 1^ inch in diameter, belonging 

 io French lamps, a tin coffee-strainer, a piece 

 of fine gauze, and a very fine cambric pocket- 

 handkerchief. A little muriatic acid was ob- 

 90 



| tained at the apothecary's. The soil to be 

 1 analyzed was taken from a piece of good 

 arable land on the south side of the slope of 

 ' the Jura mountains in Switzerland. Its spe- 

 j cific gravity was taken as described before, 

 I and found to be 2-358 nearly. 500 grains of 

 i the dry soil were stirred in a pint of water, 

 ! and set by in a basin. To save time, 500 

 ! grains more of the same soil were weighed, 

 I after having been dried over the fire. It \\ as 

 well pulverized \vith the fingers, and sifted 

 through the coffee-strainer, then through gauze, 

 and, lastly, through the cambric handkerchief. 

 Some portion was left behind at each silting. 

 ! The two first portions were washed in the 

 | strainer and the gauze. The residue was sand 

 j of two different degrees of fineness, which, 

 when dried, weighed, the coarser, 24 grains, 

 the next, 20 grains. The earth and water 

 which had passed through the strainer and 

 the gauze were now strained through the cam- 

 bric, and left some very fine sand behind, 

 which, dried, weighed, and added to what had 

 remained on the cambric, when sifted in a dry 

 state, weighed 180 grains. All that which had 

 gone through the cambric was mixed with 

 water in a jug and stirred about. The heavier 

 earth subsided, and the lighter was poured in 

 one of the lamp-glasses, which had a cork 

 fitted into it, and was placed upright. In 

 about two minutes there was a deposit, and 

 the lighter portion was poured into a similar 

 glass, where it was left some time to settle. 

 In this a slower deposition took place, and in 

 about a quarter of an hour the muddy water 

 was poured off into the third glass. The three 

 glasses were placed upright, and left so till the 

 next day. In the first glass was some very 

 fine earth, apparently clay; in the second the 

 same, but more muddy; and in the third no- 

 thing but thin mud. The contents of No. 2 

 were divided between No. 1 and No. 3, by 

 pouring off the muddy part into No. 3 after 

 some of the pure water had been poured off, 

 and the remaining earth into No. 1 ; they were 

 then left to settle. As much water as appeared 

 quite clear over the sediment was decanted off. 

 The sediment was poured on a plate by taking 

 the cork out of the tube, which was cleaned 

 with a piece of fine linen, which had been 

 carefully dried and accurately weighed. The 

 plates were examined, and some of the lighter 

 part, which floated on the least agitation, was 

 poured from one plate to another, until it was 

 thought that all the humus had been separated. 

 Most of the water could now be poured off the 

 earths, by inclining the plates gently, without 

 any muddiness. It was, however, passed 

 through a piece of filtering-paper, which hau 

 been previously dried and weighed. The 

 earth was slowly dried, by placing the plates 

 on the hearth before a good fire, until they 

 were quite dry, and so hot that the)'- could not 

 be easily held in the hand. The deposit left 

 in the jug was poured on a plate, and a little 

 muddy part, which was observed, was poured 

 j off with the water on another. This was again 

 transferred, and the finer added to that which 

 was in the second plate. Collecting now all 

 the separate portions, there were found 



