118 



NEW ENGLAND FARMER. 



April 



SAND. 

 This earth derives its name from silex. It is 

 one of the most abundant of the original earths, 

 and distinguished by the circumstance of its form- 

 ing "%utreous earth," or glass, when combined 

 with alkalies. Quartz is almost entirely composed 

 of silex. The old chemists supposed it to be the 

 primitive earth, and it was hence denominated the 

 "elementary earth," from which all the other vari- 

 eties of soil proceeded. It exists in nature much 

 more abundantly than any of the other earths, and 

 is a constituent of all hard stones which emit 

 sparks when struck with a steel ; "in the enor- 

 mous mountain masses of granite, porphjTy and 

 gneiss," as of the boundless accumulations of sand 

 in deserts and plains. In all of these silex is a 

 preponderating ingredient. Verj* few stones are 

 entirely destitute of silica, and it is found in the 

 ash of almost every plant after burning, which 

 leaves only the mineral ingredients, the other con- 

 stituents being destroyed by combustion. Gi'asses 

 contain it in very liberal and even hirge propor- 

 tions sometimes, as do also the straw of wheat, 

 rye, oats and other cereals — the stalks of the corn 

 plant, &c. It has also been detected in the skin 

 of animals. It is, however, but rarely found in a 

 state of absolute purity. Even in quartz, which 

 is mostly composed of it, we detect both alumina 

 and oxide of iron. It probably does not exist in 

 nature in a state of perfect drjTiess from extrane- 

 ous matters, and it is only by artificial processes 

 that it can be exhibited in its purity. In the lab- 

 , oratory of the chemist it is to be seen in the form 

 of a "fine, white powder, adhering a little to the 

 fingers, and exhibiting a kind of gritty roughness 

 when pressed or rubbed. It is totally devoid of 

 both taste and smell. It undergoes no changes 

 when subjected to the action of fij-e, and neither 

 fuses nor volatilizes, whatever degree- of heat may 

 be applied." 



It has no affinity for water, and cannot be dis- 

 solved even in the minutest portion, unless through 

 the agency of an intermediate body, but when 

 mixed with water, it immediately precipitates, and 

 no part of it is left in solution. No acid, except 

 the fluoric, is capable of acting upon, or dissolv- 

 ing it. It may be boiled in sulphuric, nitric or 

 muriatic acid, without even the minutest portion 

 of it being taken up. With fluoric acid it forms 

 a gaseous compound, and when the acid is evap- 

 orated, goes with it. It does not imbibe water 

 with avidity, and this fact shows why sandy soils, 

 or those which contain a preponderating quantity 

 of silex, are generally so dry and so incapable of 

 sustaining vegetable life, except when filled with 

 humus, or some similar substance which possesses 

 absorbent and retentive powers. All the fixed al- 

 kalies, however, possess the power of readily unit- 

 ing with and dissolving it ; hence the utility of 



alkalescent applications on sandy lands, and the 

 powerful agency they exert in promoting the de- 

 velopment of the straw of wheat, oats and other 

 grain crops, to the perfection of which silex is es- 

 sential. Silex, or siUca, is an ingredient of fel- 

 spar and mica. Felspar, by Von Thaer's tables, is 

 composed of 



» Paris. 



Silica ,. .^ .,♦»». . . . .^^ ,^». .62.82 



Alumina 17.02 



Lime 3.00 



Oxide of iron 1.00 



Potash 13.00 



Loss 3.19 



Total ..100.00 



In common mica we find 



Parts. 



Silica ^. ......... ....,.-, ►,-.-. .47 .00 



Alumina 20.00 



Oxide of iron ^ 15.55 



Oxide of magnesia 1.70 



Potash 14.55 



Loss 1.2d 



Total 100,00 



Sand is of thi'ee varieties, as classified by geol- 

 ogists, viz., river sand, pearl sand and moving sand. 

 The first presents a fine, clear, colorless grain ; the 

 second is composed of larger grains, which are 

 spherical shaped and semi-transparent. The po- 

 sition of this variety is generally subterranean, 

 but it is often washed up by running water. The 

 third is composed of gi'ains of divers size and 

 shape, and not unfrequently a mixture of calcare- 

 ous matter with it. 



Von Thaer, in his "Principles of Agriculture," 

 in speaking of this earth, says : 



"Although the grains of sand are, for the most 

 part, composed of silica, they always contain small 

 portions of alumina and oxide of iron. Sand has 

 as little attraction for water as pure silica, and 

 thence, as well as its not having the attraction of 

 cohesion for /;i{??ii<.?, arises the sterility that attends 

 soils composed in too large proportions of thia 

 earth. AVhen the sand is united into hard masses 

 by adhesive matter, such as clay or lime, or by 

 mechanical compression, it is called 'sand stone.* 

 There are various kinds of this substance, all va- 

 rying from each other in fineness and density. 

 They are taken out of the ground in a soft state, 

 and cut for building purposes ; to make door 

 jambs and window sills ; also, mill stones and 

 wheels for grinding and polishing tools, are made 

 of them." 



The sand stone was formerly scarce. It is now 

 procured from Saxony, and is an important arti- 

 cle of commerce. 



Sandy lands should, if possible, when intended 

 for cultivation, be dressed with clay. Some of 

 the best and most productive soils in New Eng- 

 land owe their extreme fertility to this process, 

 and are thereby fitted for growing every descrip- 

 tion of vegetable with greater success and certain- 

 ty as to maturation of crop, than many of our best 

 &oils. 



The quantity of clay which may be necessary 

 thoroughly to ameliorate sandy lands, will, of 



