318 



Lime as a Manure. 



Vol. VII. 



rough; this is merely from the decomposition 

 of the glass — now water alone will produce 

 no such effect upon glass; the living plant 

 communicates by its roots through the wa- 

 ter, (for the roots are generally not in con- 

 tact with the glass) an influence powerful 

 enough to separate the potash of the glass 

 from its strong combination, and transfer it 

 to itself: — with the knowledge of such facts 

 in our view, we are not left to the necessity 

 of rejecting a belief in the existence of any 

 process in vegetable life, merely because it 

 cannot be explained by the laws of inorganic 

 chemistry." 



I make the following extracts from Lie- 

 big's Agricultural Chemistry, New World 

 edition, 1842, page 9, on the article Humus: 



" Woody fibre in a state of decay, is the 

 substance called humus." " The carbonic 

 acid which protects the undecayed humus 

 from further change, is absorbed and taken 

 away by the fine fibres of the roots and by 

 the roots themselves ; this is replaced by at- 

 mospheric air, by which process decay is re- 

 newed and a fresh portion of carbonic acid 

 formed." " The roots perform the functions 

 of the leaves from the first moment of their 

 formation ; they extract from the soil their 

 proper nutriment, namely, the carbonic acid 

 generated by the humus." 



How will this theory be sustained by the 

 results, so far as we have had experience 1 



If this be the true theory, lime should be 

 spread upon the surface in the state of a 

 fine powder, and suffered to lay upon the 

 surface until it became mild by the absorp- 

 tion of carbonic acid gas — for the object is 

 to obtain the carbonic acid to unite with the 

 lime, from the air, and not from the earth ; 

 for if the lime is placed in a situation to ob- 

 tain carbonic acid from the earth or the de- 

 caying humus of the soil, no advantage would 

 be gained; it being very probable that living 

 plants can assimilate the carbonic acid more 

 easily from decaying humus, than from car 

 bonate of lime — but if the lime absorbs the 

 carbonic acid from the air, it is a quantity 

 fixed in the soil in addition to what before 

 existed there, as manure, decaying humus, 

 &c. — So far as we have experience, it is, I 

 believe, decidedly in confirmation of the 

 theory. I applied lime to my grounds many 

 years ago, putting it on at the same time 

 with the stable manure to the wheat crop, 

 and with some care to have them ploughed 

 in too-other, without exposure to rain or (\e\v; 

 the results were so discou racing, that I dis- 

 continued the use of lime for some years- 

 the wheat crop was generally injured, al- 

 though good crops of grass succeeded, whicl 

 should have been the result according to the 

 theory — the carbonic acid gas, given out by 



the decomposing manure, instead of being 

 made available to the growth of the wheat, 

 became absorbed by the lime, thus diminish- 

 ing the proper support of the wheat, but 

 which was afterward furnished to the grass. 

 Thirty or forty years ago, when little lime 

 was used as a manure, it was occasionally 

 mixed in the dung-hill; but more frequently 

 mixed with corn-stalks and decaying vege- 

 table matter, as a kind of compost; these 

 methods of using it have been abandoned, 

 as improper; which should be the result ac- 

 cording to the theory. 



According to this theory, there should be 

 no disadvantage from using lime, (so called) 

 much mixed with magnesia, as the latter 

 requires about as much carbonic acid for its 

 saturation as the former; it is more soluble, 

 and in particular, is more acted upon by am- 

 monia, but requires more time for its satura- 

 tion with carbonic acid gas; it would there- 

 fore, require some longer time than pure 

 "ime, before being ploughed down. 



From recently published analyses, it ap- 

 pears that the lime of the great valley, or 

 range, passing through Montgomery, Ches- 

 ter, Lancaster and York, is nearly one half 

 magnesia. Of this lime, millions of bush- 

 els are annually sold as a manure, and used 

 in Jersey, Pennsylvania, Delaware and Mary- 

 land, with results so encouraging, that the 

 demand has increased more than ten-fold, 

 within ten years. 



From the circumstance that lime is found 

 in small quantities in some vegetables, it has 

 been supposed that it is useful only for the 

 purpose of furnishing the requisite quantity 

 of lime thus found in their substance ; — late 

 experiments made by incinerating vegetable 

 matters, go to show that 50 bushels of lime 

 per acre, would not be taken up in an hun- 

 dred years, by those plants in which it is 

 found to exist in the largest proportion. 



It may properly be objected, that if the 

 roots of plants can and do decompose the 

 carbonate of lime in the soil, and use the 

 carbon or carbonic acid gas, for their own 

 growth and nourishment, that the lime would 

 again be caustic and uncombined. It is, how- 

 ever, a possible case, that plants may possess 

 that power, and that they may not always 

 be obliged to use it: it is known that in dark 

 cellars and covered places open to air, but 

 not to light, that nitrates are formed; and in 

 whatever way any acids may be formed in 

 the earth, having more affinity for lime than 

 the carbonic, the latter would be ejected 

 from its combination with the lime, which 

 would unite with the stronger acid, (if the 

 nitric, forming a soluble compound and sink- 

 ing away in the earth,) in which case the 

 carbonic acid gas would be uncombined, and 



