266 ELEMENTARY COMPOSITION OF MANURE. 



being buried, it is spread upon the herbage in full growth. The 

 plan of top-dressing is often of great use, and is another and a prac- 

 tical proof of how little detriment results from leaving manure ex- 

 posed to atmospherical vicissitudes. The procedure by top-dressing 

 has arisen from necessity : it was first resorted to with the view of 

 giving the land an addition to the inadequate dose of manure which 

 it had received before it was sown ; but it has been found to answer 

 so well in many districts, that it has been continued. We have em- 

 ployed it at Bechelbronn upon various occasions, even to hoed crops, 

 and with decided advantage, the main one being, that time was gained 

 for the production of manure. 



In the district of Marck, the practice of top-dressing lands sowed 

 with winter grain, is rapidly gaining ground; the dressing takes 

 place when the blade is already above ground ; and experience proves 

 that the passage of the wagons over the field, and the feet of the 

 horses and the men, cause no appreciable mischief; all traces of 

 them very soon disappear. Nevertheless it is decidedly better to 

 take advantage of a hard frost, when the land will bear carts, 

 &c., for the performance of the process. This plan, according to 

 Schwertz, is found to answer extremely well in Switzerland, for 

 hemp, and indeed for almost every thing else. In my opinion, top- 

 dressing ought to be viewed as a means of giving the soil, already 

 under a crop, the manure which we had been compelled to refuse it 

 at an earlier period. Still, Thaer assures us, and his authority is 

 always of great weight, that he has loo frequently seen the good 

 effects of top-dressings to beans, peas, and leguminous crops in gen- 

 eral, not to be satisfied of the general advantages of the method, in 

 connectiim with light soils especially, in which the sowing may have 

 been late. 



The elementary composition of farm-dung is a point which is not 

 undeserving of consideration. I have made repeated analyses of 

 that of Bechelbronn, operating upon it in a medium state of decom- 

 position. The animals which had produced this dung were thirty 

 horses, thirty oxen, and from ten to twenty hogs. The absolute 

 quantity of moisture was ascertained by first drying in the air a con- 

 siderable weight of dung, and, after pounding, continuing and com- 

 pleting the drying of a given quantity in the oil-bath, in vacuo, at a 

 temperature of 230° F. 



The dung prepared in the winter of the year — 



1837-8 contained 20.4 > per cent, of 



1838-9 22.2J dry matter. 



Prepared in summer of 1839 19.6 



Medium 20.7 



Water 793 



Analysis yielded the following results : 



Ttmei •f preparation. Carbon. Hydrogen. Oxygen. Aiote Aihct. 



Winter of 1837-8 32.4 3.8 25.8 1.7 36.3 



32.5 4.1 26.0 1.7 36.7 



38.7 4.5 28.7 1.7 96.4 



Bprin«ofl838 36.4 4.0 191 2 4 38.1 



1839 400 4.3 27.6 S. 4 25.7 



" •♦ 34.5 4J 27.6 2JQ HA 



