146 THE VILLA GARDENER. 



plants consists of carbon, (which is found partly in the groimd, and partly in 

 the air,) oxygen, hydrogen, and nitrogen, which are absorbed by plants partly 

 from tiie air, and partly from the water with which they are supplied ; and 

 numerous mineral or earthy substances, which are produced from the ground, 

 but which must be dissolved in water, or reduced to the state of gas, before 

 they can be absorbed by the plant. Although it is clear that the principal 

 organs through which plants take their food are the roots and the leaves, 

 there is no doubt that some portion of it is absorbed by the green part of 

 the stem and branches. The leaves are also useful in assimilating or 

 digesting food ; and they act as organs of respiration and perspiration, by 

 throwing off superfluous air and water. It is quite evident that these various 

 functions cannot be performed properly if the surface of the leaf is loaded 

 with soot, or dust, or any other substance which chokes up the pores ; and 

 consequently syringing the leaves is one of the most important points of 

 culture in a suburban garden. The roots only take up food through what 

 are called their spongioles, from their resemblance to little sponges. These 

 spongioles consist entirely of cellular tissue and mucus ; and, as they are 

 unprotected by any epidermis or skin, they are easily rotted if exposed to too 

 much moisture ; and, on the other hand, if they are kept too dry they lose 

 their power of expanding and contracting to receive moistui-e, and to send it 

 up through the other vessels of the plant. 



220. Manures should be used with caution in suburban gardens, as the 

 plants are seldom in a state to digest properly those which are of a very strong 

 nature. Animal manure to plants is like animal food to human beings, and 

 requires a healthy frame to assimilate it. Vegetable mould, formed of rotten 

 leaves mixed with sand; and carbonate of ammonia, mixed with water, will 

 be found the best manures for delicate plants growing in a confined situation. 



221. — The soil in suburban gardens is very often in a very bad state for 

 growing plants. This is most generally the effect of want of drainage; and 

 as most suburban gardens are over watered, the water which cannot escape 

 chills the soil, and, in some cases, rots the roots of the plants. It is true that 

 the latter evil is only seldom felt; but the coldness of the soil is a fact of 

 every day occurrence, though comparatively few persons are aware of its 

 existence. " Drained land," says Dr. Lindley, "is,, in summer 10° or 20° 

 warmer than water-logged land." The reason " consists in the well-known 

 fact that heat cannot be transmitted downwards through water." Thus, neither 

 the heat of the sun nor the warm rain can penetrate to the roots of plants in 

 ill-drained land ; even boiling water poured on the surface would have no 

 effect in warming soii on which cold stagnant water naturally stands. Air 

 also cannot reach the roots of plants grown in soil of this nature ; and, as Dr. 

 Lindley obKerves, ii; is as important to permit the access of air to the roots as 

 to the leaves : "both extremities of plants feed on air, the roots more than the 

 leaves. Place a plant in a place where air can gain no access to its leaves 

 and they fall off, to be followed by the decay of the stem : roots, under the 

 same circumstances, will gradually shrink and die." — {Gard. Chron., 1849, 

 p..*35.) 



222, The principal conditions, therefore, necessary to the health of plants in 

 suburban gardens are, to keep the soil open and friable, so as to admit freely 

 of the passage of minute particles of air and water to the roots of plants ; to 

 syringe the leaves of the plants as frequently as possible, so as to keep them 



