AND HORTICULTURAL REGISTER. 



PUnLISHED BY JOSEPH BRECK & CO., NO. 62 NORTH MARKET STREET, (Agkicdltuhal VVaeehoose.) 



VOL.. XVII.] 



BOSTON, WEDNESDAY EVENING, FEBRUARY 6, 1839. 



CNO. 31. 



AGRICULTURAL. 



(From the Journal of the Franklin Institute.) 



}n the part which the soil acts in the process of veg- 

 etation. Memoir read at the Jtcademij of Sciences, 

 by J. Pelletier. 



Translated from the Journal de Pharniacie, for tile Jour- 

 nal of tlifi Franklin Institute, by J. Griscom.l 



The ground is the support and nurse of plants ; 

 a its bosom, by means of roots, they seek for and 

 nd a portion of their nourishment. But to this 

 ■utii, so simple and obvious, are attached questions 

 fa complicated nature, and of the highest interest 

 5 physiology and agriculture. With one, among 

 thers, I have been particularly arrested, and it 

 as been the object of my meditations. Before I 

 ntc. upon it, permit me to bring into view some 

 icts which appear to be necessary to the discus- 

 ion of it. 



The earth is not an elementary substance. Its 

 xterior bed, the residence of plants, is formed of 

 ariiius metallic oxides, silica, alumina, lime, to 

 ■hich are often joined magnesia and the oxide of 

 on. It contains, moreover, the detritus of organic 

 tatters which had before possessed life and exis- 

 ;nce. Thu.s constituted, and under the influence 

 f air, water and imponderable fluids, the earth is 

 iniiiontly fit for the development of germs deposit- 

 d ill its bosom, and to the growth of the vegeta- 

 les which flourish upon it. 



The necessity of the presence of organic mat- 

 !r, to coii.stitute a soil, endowed in the highcsi 

 egree with vegetative force, cannot be considered 

 oubtful. In vain did Tull, in 1773, attempt to 

 laintain tliat distinct earthy particles formed the 

 ale nourishment of the plant. This theory was 

 verturned by the positive experiments of Duhamel 

 'ho had at first embraced it. Nevertheless, if it 

 5 certain that the presence of organic matter is a 

 ondition of fertility, we may still ask whether it 

 s so essential a condition — such a sine qua non, — 

 hat a plant cannot vegetate in a soil totally de- 

 rived of organic matter, particularly if other cir- 

 uiustances, such as the presence of water and 

 atbonic acid, be united with it. 



Numerous experiments have been made to re- 

 olve this question. Many of them are contradic- 

 Dry. The greater portion, from the high interest 

 'liich they involve, ought to be discussed and re- 

 •eated with care. But another question not less 

 nnportant, and which I think ought to be first as- 

 ertained, is this : ItTiat influence have soils them- 

 (Ives in the act of vegetation °? To this question I 

 .t present confine myself. 



A vegetable soil, in its normal state, must be 

 onsidered a mixture of various earths, that is, of 

 iBtallic oxides. 



Every soil devoted to agriculture, is in general, 

 ays Chaptal, formed of a mixture of silica, lime 

 nd alumina, and in support of this assertion he 

 ites various analyses.* 



I * A fertile soil in Sweden was found by Bergman to 

 onsist of: ' 



Davy confirms this statement in his Agricultural 

 Chemistry, and, in fact, not a single instance of a 

 fertile soil has occurred, which consisted of only 

 one earth, or even of two, such as lime and silex, 

 silex and alumina, alumina and lime. 



. In another passage in his Chimit Agricole, Chap- 

 tal expresses himself thus: 



" A mixture of lime, silex and alumina forms the 

 basis of a good soil ; but that it may possess all 

 the desirable qualities of good land, these ingre- 

 dients must exist .in certain proportions, which anal- 

 ysis of the best soil can only establish. 



If we consult the analysis of the most fertile 

 soils, we find that fertility diminishes in proportion 

 to the predominance of either of these principal 

 earths, and that it becomes almost null when the 

 mixture has the properties of only one ot them." 



Complexity of composition is therefoie, in gene- 

 ral, a condition of fertility in a vegetable soil. 

 Tlif loose earth which we find in valleys arising 

 from the decomposition of primitive rocks, makes 

 generally an excellent soil. Now we know that 

 granite, composed of quartz, feldspar and mica, 

 and frequently amphibole, must yield by its com- 

 position, a soiUcontaining silica, lime, alumina and 

 a little magnesia and sometimes potasii. Soils 

 originating, on the contrary, from tlie decomposition 

 of more simple rocks, siliceous limestone, for ex- 

 ample, are lighter, and suitable only for a limited 

 number of plants; they require, says Chaptal, to 

 be enriched, and are valuable only in moist cli- 

 mates. Land originating in the decomposition 

 of trap, basalt and other rocks of complicated 

 elements, possesses, on the contrary, great natural 

 fertility. 



" Rivers," he further adds, " receive in their 

 courses other streams whose mud is mingled with 

 its own, and it often happens that the united sedi- 

 ment of two rivers possesses greater fertility than 

 that of either separately." 



This then appears to be an established fact, that 



100 

 A fertile soil in Middlesex gave Davy — Siliceous Sand 

 3-5 ; the remaining 9-5 consisted of 



Carbonate of Lime, 28 



Silica, :'2 



Alumina, 29 



Analysis of a fertile soil in TouraiVie ; 



Sand, 49 



Silica, 16 



Alumina, ' 10 



Carbonate of Lime, 25 ' 



100 

 A very fertile compost, formed by Tillet consisted of 

 clay 3-8, pulverised limestone J-8, sand 2-8, correspond- 

 ing to 



Coarse Silex, 2.5 



Silica, 21 



Alumina. 16.r)0 



Carbonate of Lime, 37.50 



100 



a soil (independently of organic matter) is the 

 more fertile as its composition is more heterogene- 

 ous. 



If we seek for an explanation of this fact, we 

 find in authors only vague opinions and doubts ; 

 the greater number merely state the facts without 

 attempting an explanation. 



Agricul"ural chemists, who indulge more in the- 

 ory, appear to regard the cause of fertility as de- 

 pendent on the physical character- of the soil rath- 

 er tlian on its chemical constitution. Thus Davy 

 having observed that different soils attract moist- 

 ure with different degrees of energy, ai)<f having 

 discovered, as he believed, that the most hygro- 

 metic soils were the most fertile, he ascribes their 

 superior fertility chiefly to this property. But 

 Davy has not proved that the hygrometric force 

 of a soil bears any given relation to its composi- 

 tion. 



If this attraction of moisture were the principal 

 cause of fertility (abating the influence of manures) 

 we perceive no necessity for the combination of 

 the three earths in the constitution of a soil of the 

 first quality. Indeed a certain quantity of alumiiia 

 in a soil otherwise entirely siliceous, or entirely 

 calcareous, a certain proportion between the adhe- 

 sive and the loose or sandy portions, would be suffi- 

 cient to confer^ this ^hygroscopic quality, and of 

 course the fertility of the soil. But we have no- 

 thing to confirm this supposition. 



The hygroscopic quality of a ternary soil may 

 then he corsidered as an element of fertility, but 

 only a secondary e'"ment, subordinate to its che- 

 mical composition. 



The property of becoming more or less heated 

 by the rays of the tun, which appeared to Davy 

 to hold a relation to the fertility of different soils, 

 appears to me to be also a secondary cause. In 

 the cases referred to by hiim there was a mixt- 

 ure of black mould, and he did not sufficiently 

 consider its fertilizing action as a manure upon the 

 soil. 



To me, it appears evident, that the mixture of 

 the various earths which compose a soil, acts upon 

 vegetation and determines its fertility hy an electro- 

 chemical force, whose action has been clearly re- 

 cognized in other circumstances, but not yet brought 

 into view in the case now undeDconsideration. In 

 the first place, let us observe, that it is a fact, 

 though the truth may have escaped observers, or 

 rather, it has not yet been brought under a formula, 

 that the silica, alumina and lime which enter into 

 a good vegetable soil, must not be combined with 

 each other, but simply mixed, the lime being in the 

 state of a carbonate. A triple silicate of lime or 

 alumina, in which the silex, lime and alumina should 

 be in the proportions which constitute the best ara- 

 ble land, could not, even if thoroughly divided, 

 furnish a soil essentially adapted to vegetation. 

 If, in a fertile soil, composed of a mixture of lime, 

 alumina and silica, a combination between these 

 three oxides should begin to take place, the ground 

 would become cold and sterile. Now, it is certain, 

 that in a mixture of these three ingredients, a force 



