516 On the Growth of Barley hy different Manures, S^'c. 



in 1844 had produced an enormous increase, and to whicli the unscientific 

 and ignorant farmer would certainly, on account of this result, have attri- 

 buted a ]5reponderating value, lost, in 1846, their effect, although applied in 

 the same quantity, and in the same proportions, to the same soil ; and thej^ 

 lost their effect in the subsequent years, in the same degree * as they had at 

 first produced a favourable result. The increased produce of the first year 

 determined the diminished produce in the second and third years." 



Here then, the deficiency of only 124 lbs. (134) of hay on the 

 sal-ammoniac and phosphate plot in 1846, is attributed to its 

 larger produce by 8684 lbs. in 1844. Further, this large increased 

 produce in the first year, is said to determine the diminished 

 produce in the " second," as well as in the third year. Baron 

 Liebig does not quote the produce of the second year ; but on 

 reference to Kuhlmann's Paper, it is found that, instead of a 

 " diminished" produce in the " second" year on the plot yielding 

 the 8684 lbs. more increase than the sulphate of ammonia in 

 1844, tliat plot gives 240 lbs. more hay than the latter in the 

 " second" year, 1845, when both were unmanured. Lastly, 

 having omitted to quote the result of the second year, 1845, whicli 

 was contrary to that stated, Baron Liebig speaks of the excess 

 of 8684 lbs. of hay by the sal-ammoniac and phosphates in the 

 first year, 1844, as the cause of the defect by the same manure of 

 only 124 lbs. (134), in the third year. He treats these amounts 

 as equal, thus — " they lost their effect in the subsequent years, m 

 the same deyree as they had at first produced a favourable result." 

 Or, if the meaning were, that the sal-ammoniac and phosphates 

 should, again in 1846, have given 8684 lbs. more increase than 

 the sulphate of ammonia, and that, in this sense, the loss of 

 effect was equal to the previous gain, this argument even, is 

 quite inadmissible^ as the comparative productive characters of 

 the seasons are not taken into the calculation. 



It is presumed that the best and only refutation needed, of the 

 applicability of such evidence, and such reasoning, to establish 

 the points in question, is to put them clearly liefore the reader. 



How far it be really the case, that tlie inefficiency of the unreco- 

 vered supposed residue of nitrogen after the application of a nitro- 

 genous manure, is due to the excessive exhaustion of mineral con- 

 stituents, under the influence of the portion active and recovered — 

 it requiring the peculiar action of additional salts of ammonia to 

 set mineral constituents free and available — may perhaps be judged 

 of by the results recorded in the foregoing pages, on the growth 

 of barley after 10 years of turnips differently manured. During 

 the growtii of the 10 turnip crops, some of the plots had received 

 every year enormously more of all the mineral constituents of the 

 barley crop, except silica, than the turnips removed. The latter 



* The italics here are our own ; those in the earlier part of the paragraph are 

 Baron Liebig's. 



