THE SOUTHERN PLANTER. 



107 



portion to. the supply of ammonia ! We be- 

 lieve this method of estimating the action of 

 ammonia fundamentally erroneous. Certainly 

 we do not know of a single result, in these or 

 any other experiments, that shows the ammo- 

 nia of soluble salts to remain in the soil over 

 ojie year, when wheat is grown, and when suf- 

 ficient minerals are present to enable the plants 

 to lake up ail the ammonia they require. Let 

 us suppose a case, and one which is clearly 'de- 

 dueible from the experiments. The continu- 

 ously unmanured plot gives 15 bushels of 

 wheat per acre; a plot adjoining-, dressed with 

 30 lbs. qt' ammonia, gives 20 bushels per acre ; 

 another lot, dressed vviih 60 lbs. of ammonia, 

 gives 25 bushels; another, dressed with 90 lbs., 

 gives SO bushels; and another, receiving 120 

 lbs., 35 bushels per acre. The next year, all 

 these plots receive no manure, and the pfoMte 

 is the same on each, neither more nor less than 

 that from the continuously nnmanureJ- plot. 

 What deductions should we make Iran? stich 

 facts'? According: to Liebig's view, the first 

 plot would contain, the second year, no ammo- 

 nia ; the second plot would contain 24 ib-\ ol 

 anT'monia ; the third. 43 fbs. ; the fourth, 72 ibs. ; 

 and the fifth, 90 lbs. of ammonia per acre. 

 Now, if this be true, surely the produce would 

 not be alike on all the plots ! A direct applica- 

 tion of ammonia has al ways given a definite 

 increase, and we cannot see why the annnonia 

 remaining in the soil from the previous year 

 should not also give an increased yield. The 

 fact that it does not is clearly established^ no) 

 only by these experiments, hut by the. experi- 

 ence of hurtdreos of practical farmer?, who 

 have used salts of ammonia, Peruvian guano. 

 &c. ; and we feel warranted in concluding from 

 these facte, thai ammonia is ail used up the first 

 year — unless Liebig, or those who. agree with 

 him on this point, can bring forward better 

 argument to the contrary, than the simple, un- 

 susfained assertion that it is "perfectly impos 

 eible." 



Is it not more consistent with the facts of the 

 case to suppose that the ammonia, being quite 

 soluble, is all taken up the first year; and that 

 in the growth of wheat there is, for some pur- 

 pose or other, a great destruction of ammonia? 

 It is well kttown that plants give off' oxygen, 

 and in the absence of light, carbonic acid ; 

 why may they not also give off' ammonia? 

 Chemists have always had a difficulty in ac- 

 counting for the manner in which silica is de- 

 posited on the straw of the wheat plant. Prof. 

 Way has shown that ammonia and silica, in 

 certain double salts, form slightly soluble com- 

 pounds, and he suggested that in this form the 

 silica and ammonia is taken up into the plant ;, 

 and thrit when the silica is deposited, the am 

 mania evaporates into the air. Our object is 

 not here to deride whether this be so or not ; 

 vjc wish merely to show that Liebig has no 

 right to assume, as he has done, that it is ' per- 

 fectly impossible " for plants to take up more 

 ammonia than they contain when grown, and 

 found an argument on the assumption. He 



would have shown a better spirit, had he met 

 the views of Mr. La wee and Pro!'. Way on this- 

 point with some argument, rather than by ig- 

 noring them altogether, arid reasoning as tho ! . 

 nothing had been said in regard to it. 



The whole question appears to us to turn or* 

 this very subject, which Liebig lias entirely 

 overlooked in his review of Lawes' experi- 

 ments. If it be tr«o that wheat and the other 

 cereal grasses need for their production a much 

 larger quantity of ammonia than they contain* 

 when grown, and if on the other hand/turnips, 

 beans, peas, tares and clover do not, we have 

 at; once an explanation of there gradually de- 

 veloped systems of rotation which an enlight- 

 ened experience has proved judicious. We' see 

 at once why two grab) crops should rfo't follow 

 each other; why clover and reas and beans 

 are the best crops to precede wheat, and why 

 fin; turnip, 'in the Norfolk system ofJJridsft 

 agriculture, is such an excellent crop to pre- 

 cede barley. Indeed, we do not know of o?.&. 

 solitary well-established fact that is opposed to 

 th|s view; and surely, if it be correct, nothing- 

 can be 'mere important to a correct I under- 

 standing of rational agriculture. It is true,, 

 that it points to no .revolution in cur present 

 system of culture, and in this respect, will be 

 less acceptable to all ultra reformers j but it 

 explains the rationale of the most approved 

 systems of rot a lion and gen era! farm manage- 

 merst, confirms what practical farmers, have 

 previously but indistinct! y perceived, and urge.? 

 then? to carry out still further, and by more 

 economical methods, a system of improved 

 culture they have already commenced. 



In Germany Liebig's pamphlet has pro- ' 

 duced considerable excitement. I)r. Wolff, 

 ■^Professor of Chemistry in the celebrated Ho- 

 lt en beim Academy of Agriculture and Forest 

 Culture, and a man who, in the language of 

 Mr. S. W. Johnson, of. Yale College, unites 

 " eminent scientific ability with practical 

 knowledge," has written a masterly reply to 

 Liebig, and enters warmly into the defence of 

 Messrs. Lawes & Gilbert, whose scientific re- 

 putation the great advocate of the ' ; mineral 

 theory" has savagely assailed. This has 

 called forth another paper from Prof. Liebig, 

 and which has been translated by Mr. S. W. 

 Johnson, and will be found in the " Country 

 Gentleman," (Oct 1 1, Nov. 8). The greater 

 portion of it has only a remote bearing upon 

 the subject under discussion. Prof. Lieb?|j 

 appears to avoid, as much as possible, the 

 real issues of the question. When the result 

 of any of Mr. Lawes' experiments throw doubt 

 on Liebig's views, he cries out, " Must not 

 every farmer see that conclusions founded 

 upon experiments conducted in a manner so 

 rough, so utterly lacking circumspection, are 

 utterly valueless !" But when any of the re- 

 sults of these same experiments confirm any 



