334 AlIMONIA AND NITRIC ACID. 



atmosphere and the assimilable mineral substances added ammally to 

 the soil by the action of the weather.' He says further : — ' If the 

 farmer were to confine his business entirely, e.g. to the manufacture of 

 heer, spirit, sugar, starch-meal, dextrine, vinegar, &c., and the sale of 

 animal products merely to butter, using up the skimmed milk ; if for his 

 dairy he were to buy none but full-grown cows and not breed them 

 himself, thus endeavouring to keep the phosphates upon his farm, then 

 he Avould not only preserve continually the mineral substances in his 

 store of manure, but he would also increase them by the yearly process 

 of disintegration, imless he preferred to alienate the latter in his produce 

 (s. 142). 



Hence the point of his practical teaching, in direct opposition to his 

 theoretical, is that, in order to obtain uniform crops, great care must 

 be taken to maintain and restore the composition of the soil. 



The practical man proves that the notions which he has conceived 

 are entirely inapplicable in his practice; and that the scientific 

 principles which he disputes are precisely those by which he is un- 

 consciously guided. Sound practice and true science are ever in 

 tmison ; and a contest on these matters is possible only between two 

 persons, one of whom does not understand the other. The chief fault 

 lies in" want of precision in defining things, and in using indefinite or 

 vague language to express our ideas. 



The opinion of Rosenberg-Lipinsky (see his ' Practical Agriculture,' 

 b. ii. Breslau : E. Trewends, 1862), is ' that no kind of plant actu- 

 ally exhausts the great storehouse of the soil ' (p. 738) ; and further, 

 * that plants, directly and indirectly, return to the soil more strength 

 than they take from it' (p. 740). This opinion is thus modified 

 (p. 742) : — ' when therefore the farmer does not take suflScient care 

 that the more important magazine of nutriment, the soil, receives 

 at the right time, and in proper quantity, the necessary compensation 

 for that which is inevitably consumed, the picture of exhaustion which 

 the cultivated plants manifestly wear, cannot possibly be charged upon 

 their consumers, but the blame is wholly and solel)/ attributable to the 

 farmer himself.' Further, at p. 740, he says, ' Only in those plains, 

 where the injustice of the elements, or of man, has violently disturbed 

 the natural laws of the nutrition of plants, does the scanty vegetation of 

 the wild flora indicate the exhaustion of the soil.' 



