306 MANURES AND THEIR APPLICATION. 



constituents to serve as food for plants. Our forefathers had 

 great faith in organic matter, and though chemistry has shown 

 that they were wrong in supposing that it formed directly the 

 food of plants, yet their faith in it was not so ill-founded as the 

 supporters of what is called the "mineral theory" so vehemently 

 maintained. There is usually a kernel of truth in all doctrines 

 which for a time have received the assent of thoughtful men, 

 and the more we know of the work going on in the soil the less 

 we are inclined to undervalue the effects of organic matter. It 

 is a constituent predominating in garden soil, and in all fertile 

 soils. Consisting as it does of the decaying remains of a former 

 race of plants, it contains a considerable amount of nitrogenous 

 matter, which is slowly made available as plant food. Eecent 

 researches have discovered that it is teeming with minute forms 

 of life, consisting of microscopic germs which have the powder of 

 converting the nitrogenous matter it contains into nitric acid, 

 and that it is in the form of nitrates that the roots of plants 

 absorb the nitrogen required to form the albuminoid matter of 

 their tissues. 



We must no longer regard the fertile soil as a dead thing, but 

 rather as a world of which every cubic inch is the home of 

 myriads of living organisms busily engaged in converting the 

 decaying remains of a former generation of plants into a form 

 suitable for the nourishment of a new generation. Farmyard 

 manure is the nursery of those minute germs, which may be 

 called the leaven of the soil. The w^hole heap is swarming with 

 them, and every drop of the brown liquid which flows away from 

 a manure heap contains countless thousands of germs which if 

 allowed to fall upon a soil containing organic matter carry on 

 the great work of nitrification. 



Yet how' careless we are of this living wealth. Every farmer 

 knows that in leaving manure heaps exposed to the rain in this 

 moist climate he is losing in the constant wash that silently 

 drains away a large proportion of the best part of his manure, 

 and yet how seldom do we find any means used to prevent it. 

 Compared with the great bulk of the heap, that which tiows away 

 may seem small, but it is not so small as it seems, for it is the 

 concentrated essence of the manure. 



It is difficult to estimate its value, but there are certain data 

 wdiich enable us to form some approximation to it. 



Here is a short condensed statement showing at a glance the 

 main results of an elaborate series of analyses of farmyard 

 manure w^iich were carried out by Dr. Voelcker many years ago. 



A well-made manure heap was divided into three parts, one 

 part w'as made into a heap and left exposed to the w^eather, 

 another part was covered, and the third part was spread upon 

 the land. 



