V(ll.. S t. X<>. 7. 



AND 11 () R T f C U L T V K A L R IC G I S T K 11 



53 



ily llio more fibroin pnrts rpinain cm the mirfnco 

 I iinilorjii slotr (IccoinpDSitluii. And tlim also, ' 

 hen c.'iivprtPii into mould, pivos (int nn oxlrnct li> 

 lin wnUT, and is ihwa cnrriod down into llio soil, 

 houiih til It part of vogetsblo mould, which llcr- , 

 'litis terms cfi/if, is dirrclly biit sli>;htly gnlnbl-' ; 

 1 water, yot it has boon domon'itratcd by Tli. de 

 tussiiri> that the three constituent principles of. 

 ?gcl.>ble mould "may be converted iho nno into) 

 lO oilier, under the ulti-rnaleiy prepondemliosj in- i 

 Lience of air and water." Thus vegetable extract, 

 irbiMiaceous mould and (reino may all, by the in- , 

 jence ol" air and water, be rendered soluble and 

 5 carrii-d down into the earth. Tlio extract of; 

 ;gctable mailer, mould and seme, which thus [ 

 ingles witli water hnd descends with it into lli'? | 

 )il, IS so slightly combined with it, that the earths 

 id e.irtliy carbonates, having a stronger attrac- 

 on for it, will draw it off from the water anil fix 

 in the soil. But these earths and earthy carbon - 

 les (if there be no Inne present) will soon become 

 tturaied, and conso<iuenlly can draw no more of 

 lese ingredients from the water. The quantity 

 food for vcgelabli's laid up in store in the soil. 

 ould seem to bo limited to the amount which it is 

 pable of retaining in a state of combination. This 

 not great when lime, in some form of coinbina- 

 in, is not present, but very considerable when it 

 Tins a CMiiponcnt part of the soil. Hence the 

 eat difference in the capability of improving by 

 gctable and putrescent manures, soils which 

 ve nn.l which have not lime as one of their in- 

 edieiit-', in some form of combination. When 

 8, destitute of lime in any state of combination, 

 come completely saturated with those fertilizing 

 ■•ments which cons'itiite the food of plants, it 

 lit be supposed the remainder would continue 

 ited with the water by which ihey were carried 

 n into the soil. This would be true if there 

 Bre any chemical attraction in thr; earths to fix 

 d retain the water in combination with them, 

 til lb-? vegetable food could be drawn off by the 

 ongclets of the growing plants. But such is not 

 fact. Water will rise to the surface of the 

 rth, whence it will bo carried off by evaporation 

 d the absorbing power of the atmosphere. Rut 

 cannut carry with it the vegetable extract with 

 ich it was combined. The experiments made 

 Sir II. Davy upon grasses, as detailed in his 

 .rricul'.ural Chemistry, show that tiie extractive 

 Iter is always left as a residuum, upon boiling 

 : decoction. .Mlhough water may bring back 

 tlie surface of the earth such portions of the 

 getahle extract as may not have been drawn 

 m It by earths, having a stroiijer attraction for 

 than the water, yet it cannot bo carried off by 

 ap'iralion or absorption, and consequently it will 

 left at or near the surface of the soil. This de- 

 site of vegetable extract is one of the iiauses 

 ly vegetable mould is most abundant at or near 

 > surface of soil.s, and assists in producing " the 

 ick and brown rich vegetable mould," in which 

 ivy siys "the earths seem to be in combination 

 til a peculiar extractive matter afforded during 

 ; d-'cornposition of vegetables." Hence there 

 luld seem to be a continual accumulation of geine 

 d other vegetable matters at and near the sur- 

 :e, so long as the quantity of such matters fur- 

 hed by decaying vegetation exceeds that which 

 _s consumed by the growing plants. In the 

 ur-ie of time, this accumulation of ve^etablo inal- 

 ai the surface of the earth, would become very 

 eat if there were no means of carrying il off. — 



In calcareous soils there is a chemical airoiicy, 

 which excrtx great energy in retaining.' iiiid cmiliii. 

 ing this siiperabund'inco of vegetable food, so that 

 the accumulation becomes very considerable. But 

 in soils which are de^litiiie of ralc'ir<'oii« earth, no 

 such considerablt accumulalions are foiiml. This 

 is probably owing in pari to the nature of the vcgo- 

 tdblo growth, which may bo incapable of drawing 

 much of Its food from the atmosphTO. and conse- 

 quently the decaying vegeiation may furnish no 

 more vegetable matter to the soil than it drew 

 from it for its own noiirisliiiient. But as exhaust- 

 ed lands, even in the poorest soil, when suffered 

 to grow up in timber, are found to increase slowly 

 in fertility, il follows as a necessary consequence, 

 that in the course of time there would In- a consid- 

 erable accumulation of vi^gelable matter on the 

 surface of the soil, unless soiiio agency is at work 

 to carry off the superabundance. What that agent 

 is, and what are the best means of counteracting 

 its effects, is an important inquiry. Fmm the ten- 

 or of your "Essay on Calcareou.s Manure.s," it is 

 obvious you suppose the effect is produced by cer- 

 tain vegetable acids neutralizing any lime which 

 may formerly have composed one of the ingredi- 

 eii'softhe soil, and then combining with geine 

 and other vegetable products, and thereby rendi^r- 

 ing them unfit for vegetable food for the morn use- 

 tiil plants. If your vii'ws on this subject are cor- j 

 rect, it would seem to follow that th 're is in fact i 

 no loss of vegetable food from the want of a soil 

 to tix and retain it, but that it is only rt-nlored in- 

 efficient in consequence of its combimiion witii i 

 certain acids in the soil. And it would seem that i 

 if it were all retained in combination witli acids, ' 

 by the application of a due proportion ofcarhoiiatc 

 of lime the acrumiilaled food of plants would im- 

 modiitely become available, and the soil here- 

 stored to the highest deL'rO':> of fertility of which it 

 was capable. Tiiese views arc very encouraging 

 and you have sustained them by such proofs and 

 illustration^ as to render them extremely prcdjable. 

 The recent discovery of geine or humin, and the 

 acid found under certain circumstances by the com- 

 bination of oxygen with this base, seems to prove 

 that the existence of an acid in a soil is not always 

 prejudicial to the growth of useful vegetation. Pro- 

 fessor Rennio. as quoted in your Essay, says "hii- 

 mic acid, however, which I may remark is not sour 

 to the taste, readily combines with many of the 

 substance.s found in soils and manures, and not on- 

 ly renders them, but itself also, easy to be dissolv- 

 ed in water, which in their separate state could not 

 take place. In this way humic acid will combine 

 with lime, potass and ammonia, in the form of hu- 

 inatC't, and the smallest porticm of these will render 

 it soluble in water and fit to be taken up by the 

 spongelets of the root fibres." 



He farther remarks, " It appears to have been 

 from ignorance of th" important action of the hu- 

 mic acid ill thus helping to dissolve earthy matters, 

 that the older writers were so puzzled to discover 

 how lime and potass got into plants." Professor 

 Rennic says hnminor{iii called by B'Tzelius) g'eine, 

 is composed of carbon and hydrogen, and the addi- 

 tion of oxygen to this base to form humic or geic 

 acid. This, I apprehend, can no more render it 

 poisonous to plants than tlie addition of oxygen to 

 carbon, thereby forming carbonic acid, can render 

 that substance prejudicial to the growth of vegeta- 

 tion. This acid, so far from being prejudicial, is 

 the principal source of the supply of food for vege- 

 tables from tlie ntmosphere. 



Ber/.nliiiH Hays that "the carbonaceous mould, 

 winch changes II part of the air [Rtmosplivn.') into 

 carbonic acid, is itself changed by iho nir Into 

 geine and into tlio extract of mould ; and il m up- 

 on this transformntion thai appeurH to depend, in 

 part, the advnnta:;es derived from the tillugc of tlie 

 soil, which is divided by the ac;lion ofllie plow and 

 exposed to the Immediate influence of the air." 



EInhof has ascertained that gcino, in acid soils, 

 is combined » itii phosphoric and acetic acids; and 

 Do Pontin, il is said, has also found it combined 

 with the malic ncid. These aiitliorilies are abun- 

 dantly sufficient to prove that geine is found in a 

 state of combination with a variety of acids. Som« 

 of these combinations are found nol to bo prejudi- 

 cial to vegetation of the most useful kind, but in 

 some of its combinations it may only suit tho 

 growth of vegetables of an acid character, as you 

 have shown in your Essay on Calcareous Manures. 

 There is a point beyond which soils cannot be 

 permanently enriched, without an improvemi'nt of 

 their constitutional organization, which may be 

 done by supplying those ingredients of a good soil 

 which are deficient, such as clay, where sand ii 

 too predominant, and carbonate of lime, where 

 that is deficient, &c. 



But without a change in the constitnlional or- 

 ganization of the soil, we cannot hope to carry its 

 fertility, peimanenth/, beyond what it had acquired 

 in a state of nature. Soils which have been re- 

 duced by cullivatinn, wlide lliey have not been in- 

 jured by washing rains, may be easily renovated. 

 This must be done by again supplying ihem with 

 those fertilizing in'jrredients of which they have 

 been deprived by bad husbandry. This may be 

 accomplished in part, by the application of manure ; 

 but it is to the atmosphere we must look as the 

 great storehouse whence we are to draw the neces- 

 sary supply of vegetable food. To this end, those 

 irrecn crops should he freely cultivated, which de- 

 rive most of their food from the atmosphere. In 

 soils adapted to it, red clover is the most siiitable 

 for this purpose. It is by fir the most convenient 

 and the cheapest method of renovating exhausted 

 soils. It not only supplies a groat deal of vegeta- 

 lile matter to soils that have been much reduced, 

 but it is admirably calculated to pulverize and re- 

 duce its component parts to a finely divided slate, 

 and thus to produce a condition favorable to a com- 

 bination with tliose elementary principles which 

 are furnished by the atmosphere; and also greatly 

 increases its capacity for absorbing moisture. Care 

 should be taken also to suffer as few weeds to ri- 

 pen their seed.s as possible. These, previous to 

 the time of ripening their seeds, derive nearly the 

 whole of their nutriment from the atmosphere. By 

 destroying them before they seed, nearly their 

 whole product of vegetable matter is a net gain to 

 the soil. Exhausting grain crops should be spar- 

 inijly cultivated till the soil is completely renova- 

 ted, and then should bear only such a proportion to 

 the green crops as the soil will bear without dete- 

 riora'lion. Il should be a fixed principle never to 

 suffer the soil to deteriorate, for as it costs as much 

 to cultivate a soil producing only half or two thirds 

 of a crop, as if it produced a full crop, it is perfect- 

 ly clear that it is the interest of the cultivator to 

 keep his land always in good heart Besides, it is 

 less difficult to keep land in a state of fertility than 

 to renovate it after it has been exhausted by care- 

 less husbandry. But it is lime to bring my desul- 

 tory speculations to a close. 



A. BEATTY. 



