144 CHARCOAL AND NITROGEN. 



occasionally stirring it and drying and pulverizing the gypsum. This 

 is sold in England as urate ; but it is less valuable, as it does not con- 

 tain the soluble saline matter. But, of all substances for fertilizing 

 the soil, night-soil is the most valuable, especially when dry, as pou- 

 drette. 



Jlnimalized charcoal is now much manufactured by blending the 

 above with gypsurn and ordinary wood charcoal in fine powder. Char- 

 red peat also, mixed with it would be equally valuable. Eminently 

 fertilizing powers are likewise possessed by the deposit of all birds. 

 Of guano we have already spoken ; this is now sold in England, as 

 imported, for $4. 50 per cwt. The newly discovered process of pre- 

 paring the seed, as alluded to in a previous article, may when disclosed, 

 be of the greatest importance. And it appears to us reasonable to 

 suppose that such, or some other important preparation of the seed, 

 may readily be effected ; for it is obviously the most simple, natural 

 and effective mode of imbuing the plant with nutritive principles. 

 To return to the soil or to the plant, the elements of which the latter 

 is composed, is evidently the object of all the applications referred to ; 

 and the above last-mentioned substances are clearly those best calcu- 

 lated for this purpose. 



The amount of nitrogen which any one of these contains is said to 

 be the readiest and most simple criterion by which their agricultural 

 value, compared with vegetable matters, can be estimated. Thus the 

 relative proportions of this element, as compared with 100 Ibs. of 

 farm-yard manure, is, with a few of the more important, as follows : 

 dry woollen rags 2j, horn shavings 3, cow hair 3, feathers 3, dry flesh 

 3, manure of pigeons 5, liquid blood 15, and the various liquids and 

 solids of cattle from 16 up to 100. So 2 Ibs. of woollen rags is 

 equal, in the nitrogen or organic matter it contains, to the 100 Ibs. of 

 farm-yard manure. Still it will be seen that some of these and other 

 materials, contain more saline matter than the dry substances classed 

 as first in their quantity of nitrogen. But no one simple substance 

 can answer for a long time on the same soil ; and hence the necessity, 

 under all circumstances, of using mixed manures and artificial com- 

 posts. The principal difference between animal and vegetable sub- 

 stances, will be seen to consist in the greater amount of nitrogen con- 

 tained in the former. These are also distinguished, generally, by the 

 rapidity with which they decay when moist. Their nitrogen gradually 

 assumes the form of ammonia, as perceived by the smell ; but the 

 escape of this should always be prevented, it being the most valuable 

 property of the substances. 



The source of nitrogen supplied by the animal body may be per- 

 ceived by the facts that, whilst we receive in our food much nitrogen, 

 little or none is given off in life in the usual forms. If a man eat, 

 say llbs. of bread and 1 Ib. of meat in 24 hours, he gives off 8 oz. 



