300 



THE FARMERS' REGISTER. 



physiology'? (s it not direcily in the teeth of all 

 that is laiight us by Sir H. Davy, Chaptal, De 

 Candolle, Liebig, Buel, and every other agricul- 

 tural writer of reputation'? And lastly, is it not 

 opposed to the experience of every farmer who 

 does not live wiihin the smoke of a city, where 

 the fertility of his lots may be almost maintained 

 by the continual presence of an atmcsphere load- 

 ed with gases generated by the fiiih of a crowded 

 population 1 



It is a common observation of farmers in this 

 quarter, that when lands are worn down with 

 long continued and severe cropping, so that their 

 yield in grain is not worth the labor of cultivation, 

 they will produce a luxuriant crop of clover. 

 Not less common is the observation, that old 

 tobacco lots, when they grow tired of the crop 

 which they have borne for a long succession of 

 years, and refuse to produce the same heavily, 

 however well cultivated or highly manured, can 

 only be restored as a tobacco lot by a rotation. 

 It would be easy lo illustrate these opinions by 

 many striking examples around me; but I deem 

 it unnecessary to cumber this letter with them, 

 as I presume there are palpable illusirations of 

 their truth in every neighborhood in the state. 



We have always thought that these results 

 were perfectly natural, and consistent with the 

 organic laws of vegetable physiology. We have 

 been content with the theory, that some plants 

 require a peculiar species of food, whilst others 

 require a different. That, of course, when the 

 peculiar food of the cultivated plant was ex- 

 hausted, it was no longer capable of producing 

 if, whilst its adaptation to the growth of othe"r 

 plants, demanding a different pabulum, was un- 

 affected. We have always believed, too, that the 

 excremenlitious matters, thrown off by plants, were- 

 as incapable of nourishing plants of the same 

 kind, as the excretions of animals are of being 

 assimilated by the same species. We have be^ 

 lieved, too, that the analogy is farther maintained 

 in this, that these excretions may nourish other 

 plants, differently constituted, as the excretions 

 of one species of animals afiords nourishment 

 to another. Such have been the opinions of all 

 enlightened agriculturists for a great many years ; 

 certainly ever since the theory was revived and 

 Illustrated by the genius of De Candolle, Liebig, 

 in his great work on agricultural chemistry, 

 maintains it, with some slight modification, in all 

 essential particulars. He thinks that the excre- 

 mentitious matters suffer various transformations 

 in their passage through the organism of the 

 plant, (pp. 54 and 55,'^ till at last, being capable 

 of no further chanaes, they are separated from the 

 system, by the organs destined for that purpose. 

 That these exudations, though they may be ab- 

 sorbed, can never (until decomposed) be as.=iiTii- 

 iated by the plants producing them, while they 

 may very well be fed on by plants differently 

 organized. 



Independent of the cogent inferences from the 

 known principles of vegetable physiology, in 

 support of this theory, the experirnenis of JVIa- 

 caire Princep, alluded to by Liebig, seem lo 

 place its correctness above controversy. How 

 will Mr. Turner, except upon the principles here 

 advocated, explain the fact that plants of the 

 leguminoscB family, wither in the water in which 

 the same species have grown until the excretions 



have colored it brown, whilst corn plants grow 

 vigorously in the liquid, and the brown color di- 

 minishes sensibly with the growth of the plant. 



You will observe in this experiment, that the 

 plants selected are unlike in their organism, and 

 whilst the one fieeds largely on the phosphates, 

 the other requires scarcely any. I ask iVlr. Tur- 

 ner if the inference is not irresistible, that the 

 beans first grown in the water, had destroyed its 

 fitness to sustain a second crop of them, either 

 by exhausting the peculiar food on which they 

 fed, or by poisoning the water with their excre- 

 tions? It is not equally clear, that at the same 

 time that the liquid was thus rendered unfit for 

 the support of beans, it still retained a capacity 

 lor producing corn, and that this corn, instead 

 of rejecting, actually fed upon the exudations of 

 the beans ? If true, as is proven, with regard to the 

 water, I would again respectlully ask your in'el- 

 ligent correspondent, would it not be equally true 

 of the soil ? Can there be any difference, when 

 every thing absorbed by a plant from the soil 

 must necessarily be previously dissolved 1 I am 

 sure he will at once admit that the second fact is 

 a legitimate corollary from the first, and in so do- 

 ing his own theory loses its foothold, and falls to 

 the groimd. If this experiment were not so per- 

 fectly conclusive, it would be very easy to pile 

 proof upon proof, " Pelion upon Ossa," in support 

 of it. 



Liebig relates an instance of a landed proprietor 

 in the vicinity of Gottingen, who, to obtain pot- 

 ash, planted his whole farm with wormwood. 

 The consequence of which was, that it so effectu- 

 ally exhausted the potash in the soil, that it was 

 incapable of bearing grass for many years — the 

 grass requiring a large supply of the silicate of 

 potash. 



In combating these universally received opi- 

 nions, Mr. Turner sets out, rather ominously, in 

 the midst of a strange confusion of technical 

 terms, and an entire misapprehension or misap- 

 plication of authors quoted, and when he has thus, 

 under the delusion of an honest zeal for his theo- 

 ry, dove-tailed an ingenious and plausible argu- 

 ment, he then endeavors to varnish over the 

 whole with some striking fijcts. 



In adverting to this part of Mr. Turner's essay, 

 I will not confine myself to his precise language 

 where it is unimportant, as it would unnecessarily 

 lengthen what I have to say, but merely quote the 

 substance. 



He says there is one ingredient which is neces- 

 sary to all crops, and that ingredient is fertility ; 

 and that this ingredient is just as necessary to one 

 crop as' another. Fertility, as understood by him, 

 is synonymous with humus, as understood by 

 Prof. Webster, geine as called by Profl Dana, and 

 ammonia as maintained by Liebig. He makes, 

 in confirmation, an extract from the second report 

 on the agriculture of Massachusetts, whereof Prof 

 Dana says, " II we can induce the state of geine 

 best filled for each plant, then adieu to the doc- 

 trine of the necessity of a rotation of crops." 

 Without quoting farther at present, let us halt and 

 review the ground. 



That this fertility here referred to, and easily 

 comprehended by every farmer, is not, as Mr. 

 Turner supposes, synonymous with humus, geine, 

 &c., will be perfectly obvious when it is recollect- 

 ed that many plants, wheat for instance, will not 



