MANURES, AND HOW TO USE THEM 47 



dissertation upon chemical manures. But the subject of manures 

 and how to use them is nevertheless of such great importance 

 that no efficient gardener can afford to neglect it. 



Let us reduce the science of manuring to simple terms, and we 

 shall then see why it is necessary to obtain a firm grip on its first 

 principles. Manuring means nothing more nor less than the 

 feeding of the soil. It stands to reason that if you crop a piece 

 of ground from year to year with potatoes, or beans, or roses, you 

 will gradually rob it of essential plant foods, until at last your 

 crops will fail and your rose-trees refuse to put forth any but the 

 most mediocre type of blooms. Therefore if you exhaust the 

 ground of those elements in it which supply the needs of your 

 plants, it follows that you must from time to time repair the 

 deficiency and, for want of a better word, we call it manuring. 

 Plants obtain a fair proportion of their sustenance from the 

 atmosphere, by means of the breathing apparatus in their 

 foliage, but most of the feeding is accomplished in the foraging 

 expeditions carried on incessantly by their roots. If the roots 

 on almost any plant be examined it will be found that they are 

 supplied with smaller fibrous roots or minute hairs. These are 

 similar to the capillaries that unite and feed the blood-vessels of 

 the human body. They are tubes with bores as fine as a hair, 

 and it is through these that the food is absorbed from the soil and 

 passed on through the instrumentality of the larger roots to the 

 stem, leaves and blossoms of the plants themselves. Incidentally 

 it may be remarked that when one remembers the delicate con- 

 struction of these myriads of tiny hairlike roots the supreme 

 necessity for thoroughly breaking up the soil in the process of 

 digging and trenching is brought vividly home. The sheer 

 impossibility of efficient root-action in hard unyielding soil is 

 at once apparent. 



At the same tune another important fact in the root-feeding 

 of plant life suggests itself. This is that the capillaceous roots 

 cannot absorb the food they require in the form of solids. There- 

 fore it follows that all the many varieties of manure that are 

 employed in enriching the ground must of necessity be such as 



