470 FERTILIZING VALUES OF . \IMAL EXCRETIONS. 



constant change from the escape of those volatile compounds in which 

 the nitrogen principally exists. 



2°. A series of experiments made by Hemibstiidt upon the quantity 

 of grain of different kinds, raised in the same circumstances by equal 

 weights of different manures, gave the following results : 



Number of soads reaped from 

 Manure applied. Wheat. Barley. Oals. Rye. 



Oxblood 14 16 12i 14 



Nightsoil — 13 141 131 



Sheep's dung 12 16 14" 13 ' 



Human urine — 13|^ 13 13 



Horsedung 10 13 14 11 



Pigeon dung — 10 12 9 



Cow dung 7 11 16 9 



Vegetable matter 3 7 13 6 



Unmanured — 4 5 4 



If the results contained in this table were to be depended upon, it 

 would appea* that, in so far as the quantity of the produce is concern- 

 ed, these manures severally exercise a special action upon certain 

 crops — that night-soil, for example, is most propitious to rye, cow 

 dung to oats, and sheep's dung to barley and wheat. And the latter 

 fact would seem at once to justify and to recommend the eating off 

 with sheep preparatory to either of the latter crops. 



None of these kinds of manure, however, is constant in composition, 

 and the following observations will satisfy ysu that implicit rehance 

 ought not to be placed either upon the relative practical values of the 

 different animal manures as they appear in the latter table, nor on 

 their theoretical values as exhibited in the former. 



§ 15. Influence of circwnstances on the quality of animal manures. 



The quality of the droppings of animals considered as manures is 

 affected by a great variety of circumstances — such as 



1°. By the kind of food upon which the animal is fed. — Thus night 

 soil is more valuable in those countries and districts in which much 

 flesh meat is consumed, than where vegetable food forms the principal 

 diet of the people. It is even said by Sprengel, that in the neighborhood 

 of Hildesheim the farmers give a higher price for the house manure 

 of the Lutheran than for that of the Roman Catholic families, because 

 of the numerous fasts which the latter are required to observe. (Ijehre 

 vom Danger^ p. 142.) Every keeper of stock also knows that tJie ma- 

 nure in his farm-yard is richer when he is feeding his cattle upon oil- 

 cake, than when he gives them only the ordinary produce of his farm. — 

 [12 loads of the dung of animals fed (while fattening) chiefly upon oil- 

 cake was found to give a greater produce than 24 loads from store stock 

 fed irfthe straw yard. — Complete Grazier^ 6th edit., p. 103.] 



2°. By the quantity of urine voided by the animal. — Upon the unlike 

 quantities of urine they produce appears mainly to depend the unhke 

 richness of the dung of the horse and of the cow. The latter animal, 

 when full grown and not in milk, voids nearly 13 times as much urine 

 as the former (p. 460), and though an equal bulk of this urine is poorer 

 in solid matter, yet the whole quantity contains several times as much 



