14 



bCIENCE OF GARDENING. 



separation of parts be apparent ; then pour 

 off the floating matter, and repeat the rub- 

 bing and washing with fresh water, till no- 

 thing but sand remain in the mortar : dry 

 this sand by placing the mortar on a grate 

 or stove. In the meantime all the waters 

 being collected together in one jug or glass, 

 will gradually deposit the fine particles, and 

 the liquor will exhibit more or less color, 

 resulting from vegetable or other manuring 

 substances contained in the earth. 



This earth and water should next be well 

 mixed, and after standing quiet for a mi- 

 nute or two, be poured into another vessel 

 slowly and cautiously, because some sand 

 will pass from the mortar, and this must be 

 separated by repeated washings. 



This second process will separate the fine 

 matter of the soil, and the sediment can 

 readily be collected by pouring off the wa- 

 ter that appears quite clear, and then the 

 remainder with the sediment, either into a 

 plate or a paper filter previously weighed 

 and placed in a funnel. In either case, the 

 few particles remaining in the jug must be 

 removed by a little more water, and added 

 to the rest, or be wiped off with a piece of 

 dry linen accurately weighed beforehand. 

 The earthy sediment is to be first dried by 

 slow evaporation, and then by a heat equal 

 to that which was employed in the first in- 

 stance. All the dried products are to be 

 weighed, and when three experiments of 

 the kind have been completed, the operator 

 may reach his conclusions. Thus, of 240 

 grains, 120 may be of i\ie fine ear^ As, which 

 we call clay, as they contain all the alumi- 

 na of the soil ; 20 grains of coarse sand, 

 separated by sifting, and 90 grains oi fine 

 sand, left by the several washings. Some 

 loss there undoubtedly is, and 10 grains is 

 not too great an allowance in 240. 



By this investigation, it is evident we do 



not detect the chalk, iron, or pure clay ; nor 

 can we hope to do so, without chemical 

 agency ; but the discovery has been made, 

 how to compare one soil with another, and we 

 can now form some idea of the errors and 

 failures which attend a vague and random 

 use of terms, and no longer take it for 

 granted that the loam of a Flushing nurse- 

 ry is identical with one so called in Ohio. 



But there is also vegetable nutritive mat- 

 ter in all loams, and a portion of this is so- 

 luble in water : the actual weight of it may 

 be ascertained by taking a fourth parcel of 

 the dried, powdered loam, and keeping it 

 at a full red heat till there remain no black 

 color in the earth after becoming cold ; the 

 loss of weight will then show the quantity 

 of vegetable fibre (or of the substance now 

 called humus,) which the loam contained j 

 and thus its fertilizing qualities will be 

 more readily estimated. It is astonishing 

 to what extent sand may exist in a loam, 

 and yet leave it hard bound after watering ; 

 a sharp, harsh, gravelly grit may form three 

 parts of four of a loam that then remains 

 quite intractable ; therefore we advise the 

 gardener to attend strictly to the texture of 

 the sand which, in the best loams, is finer 

 than silver sand ; upon this ingredient de- 

 pends the softness of the loam, and its fit- 

 ness for the purposes of pot culture. If 

 equal parts of this fine earth and heath soil 

 be required for a certain tribe of plants, a 

 gardener who has only a stiff and rigid 

 loam at command, must only use one-third 

 or less of it, otherwise he must fail in keep- 

 ing his plants in health. 



Of leaf mould and manure, we must 

 speak in another article. Sand — pure sand 

 — requires no analysis ; but pit sand should 

 be washed. Heath soils differ exceedingly, 

 yet all contain iron. They only require the 

 operation of fire to ascertain their relative 



