ANALYSIS. 



ANALYSIS. 



ing plants, whilst insoluble geine becomes 

 food after sufficient exposure to air and mois- 

 ture. Hence the reason and result of till- 

 age. 



Rules of Analysis. " 1. Sift the soil through 

 a fine sieve. Take the fine part ; bake it just 

 up to browning paper. 



"2. Boil 100 grains of the baked soil, with 

 50 grains of pearl ashes, saleratus or carbonate 

 of soda, in four ounces of water, for half an 

 hour ; let it settle ; decant the clear ; wash the 

 grounds with four ounces boiling water ; throw 

 all on a weighed filter, previously dried at the 

 same temperature as was the soil, (1) ; wash 

 till colourless water returns. Mix all these 

 liquors. It is a brown-coloured solution of all 

 the soluble geine. All sulphates have been 

 converted into carbonates, and with any phos- 

 phates, are on the filter. Dry therefore that, 

 with its contents, at the same heat as before. 

 Weigh the loss is soluble geine. 



" 3. If you wish to examine the geine ; pre- 

 cipitate the alkaline solution with excess of 

 lime-water. The geate of lime will rapidly 

 subside, and if lime-water enough has been 

 added, the nitrous liquor will be colourless. 

 Collect the geate of lime on a filter ; wash with 

 a little acetic or very dilute muriatic acid, and 

 you have geine quite pure. Dry and weigh. 



"4. Replace on a funnel the filter (2) and 

 its earthy contents ; wash with two drachms 

 muriatic acid, diluted with three times its bulk 

 of cold water. Wash till tasteless. The car- 

 bonate and phosphate of lime will be dissolved 

 with a little iron, which has resulted from the 

 decomposition of any salts of iron, beside a 

 little oxide of iron. The alumina will be 

 scarcely touched. We may estimate all as 

 salts of lime. Evaporate the muriatic solution 

 to dryness, weigh and dissolve in boiling 

 water. The insoluble will be phosphate of 

 lime. Weigh the loss is the sulphate of 

 lime ; (I make no allowance here for the dif- 

 ference in atomic weights of the acids, as the 

 result is of no consequence in this analysis.) 



"5. The earthy residuum, if of a grayish 

 white colour, contains no insoluble geine test 

 it by burning a weighed small quantity on a 

 hot shovel if the odour of burning peat is 

 given off, the presence of insoluble geine 

 is indicated. If so, calcine the earthy resi- 

 duum and its filter the loss of weight will 

 give the insoluble geine ; that part which air 

 and moisture, time and lime, will convert into 

 soluble vegetable food. Any error here will 

 be due to the loss of water in a hydrate, if one 

 be present, but these exist in too small quan- 

 tities in 'granitic sand' to affect the result. 

 The actual weight of the residuary mass is 

 ' granitic sand.' 



" The clay, mica, quartz, &c., are easily dis- 

 tinguished. If your soil is calcareous, which 

 may be easily tested by acids ; then before 

 proceeding to this analysis, boil 100 grains in 

 a pint of water, filter and dry as before, the 

 floss of weight is due to the sulphate of lime, 

 iven the sulphate of iron may be so consider- 

 ed; for the ultimate result in cultivation is to 

 convert this into sulphate of lime. 



" Test the soil with muriatic acid, and having 

 thus removed the lime, proceed as before, to 

 92 



determine the geine and insoluble vegetable 

 matter. 



" In applying Dr. Dana's rules given in the 

 text, to the "soils of Massachusetts, I found it 

 iicce-.ssary to adopt some method of carrying 

 forward several processes together. I accord- 

 ingly made ten compartments upon a table, 

 each provided with apparatus for filtering and 

 precipitations, also ten numbered flasks, ten 

 evaporating dishes, and a piece of sheet-iron 

 pierced with ten holes, for receiving the same 

 number of crucibles. I provided, also, a sheet- 

 iron oven, with a tin bottom large enough to 

 admit ten filters, arranged in proper order, and 

 a hole in the top to admit a thermometer. The 

 sand bath was also made large enough for 

 receiving the ten flasks. In this manner I was 

 able to conduct ten processes with almost as 

 great facility as one could have been carried 

 forward in the usual way." 



As before stated, Dr. Dana regards geine as 

 the basis of all the nourishing part of vegetable 

 manures. The relations of soils to heat and 

 moisture, he says, " depend chiefly on geine. 

 It is in fact, under its three states of 'vegetable 

 extract, geine, and carbonaceous mould,' the 

 principle which gives fertility to soils ]<>;iu r 

 after the action of common manures has 

 ceased. In these three states it is essentially 

 the same. The experiments of Saussure have 

 long ago proved that air and moisture convert 

 insoluble into soluble geine. Of all the pro- 

 blems to be solved by agricultural chemistry, 

 none is of so great practical importance as the 

 determination of the quantity o soluble and 

 insoluble geine in soils. This is a question of 

 much higher importance than the nature and 

 proportions of the earthy constituents and 

 soluble salts of soils. It lies at the foundation 

 of all successful cultivation. Its importance 

 has been not so much overlooked as under- 

 valued. Hence, on this point the least light 

 has been reflected from the labours of Davy 

 and Chaptal. It needs but a glance at any 

 analysis of soils, published in the books, to see 

 that fertility depends not on the proportion of 

 the earthy ingredients. Among the few facts, 

 best established in chemical agriculture, are 

 these : that a soil, \vhose earthy part is com- 

 posed wholly, or chiefl} r , of one earth ; or any 

 soil, with excess of salts, is always barren ; 

 and that plants grow equally well in all soils, 

 destitute of geine, up to the period of fructifica- 

 tion, failing of geine, the fruit fails, the plants 

 die. Earths, and salts, and geine, constitute, 

 then, all that is essential; and soils will be 

 fertile, in proportion as the last is mixed with 

 the first. The earths are the plates, the salts 

 the seasoning, the geine the food of plants. 

 The salts can be varied but very little in their 

 proportions, without injury. The earths admit 

 of wide variety in their nature and proportions. 

 I would resolve all into 'granitic sand;' by 

 which I mean the finely divided, almost impal- 

 pable mixture of the detritus of granite, gneiss, 

 mica-slate, sienite, and argillite ; the last, 

 giving by analysis, a compound very similar 

 to the former. When we look at the analysis 

 of vegetables, we find these inorganic prin- 

 ciples constant constituents silica, lime, mag- 

 nesia, oxide of iron, potash, soda, and sulphuric 



