58 BOARD OF AGRICULTURE. 



any other clement than these ; but humus, or rather some of 

 the compounds which are included in that term, undoubtedly 

 have the power of combination with other substances in the 

 soil, and perhaps that of liberating elements otherwise locked 

 up within it. Thus a simple form of woody fibre in the con- 

 dition of humus, may yield nourishment to a plant having a 

 more complex or higher form of woody fibre. That such is the 

 case we think probable from the fact that an artificial soil, 

 containing but a trifling amount of organic matter, supports at 

 first plants of an inferior type ; these by their decay produce a 

 more abundant supply and a higher form of humus, and the 

 next race of plants are of a superior class ; and this action goes 

 on until a natural limit is reached. Pure woody fibre, divested 

 of every thing but its essential composition, is the same in all 

 circumstances, and it differs only in the quantity and variety of 

 the additional elements united or combined with it. The higher 

 the type of the plant from which it is derived the more value 

 does it possess as a manure for plants of a correspondingly 

 elevated composition. Thus a ton of manure, the product of a 

 comparatively low form of vegetation, such as swale hay, has 

 much less value for manurial purposes than a ton produced 

 from Timothy. 



We cannot therefore always judge correctly of the value 

 of a manure simply by measuring its bulk, but we must know 

 the materials out of which it is made. It is a fallacious 

 idea that, by composting manufe with loam, or any other 

 substance, we thereby increase the elements of that manure. 

 It is merely a dilution. The different qualities of muck are 

 without doubt dependent for their value almost entirely upon 

 the composition of the materials out of which they are formed. 

 Muck is a form of humus from decayed vegetable fibre, produced 

 without the intervention of animal life. If it has its source in 

 a low or simple type of vegetation, it will be found to have 

 much less value as a manure than if it had been derived from a 

 more elevated or complex one. It is probably true tiiat any 

 plants, or class of plants, are best nourished through the decay of 

 similar ones of a previous existence, for the reason that pre- 

 cisely the same elements, in kind and quantity, are set at liberty 

 by tin; (h^caying that are rocjuircd to build up the structure of 

 the growing one. 



