104 
THE SCIENCE OF HOETICULTURE. 
We have occasionally had to apologise for the discursive nature of our papers; 
hut there are general principles which equally apply to the garden and the field, and 
unless these be appreciated, scientific culture cannot he adopted. All effects are 
dependent upon causes ; therefore, we cannot err in adducing any theory or fact which 
tends to elucidate those causes. 
Every garden ought to be thoroughly drained, otherwise no dependence can be 
placed upon it ; cultivation cannot proceed healthily ; and even common security 
becomes very questionable : of this latter fact the writer once met with a proof 
equally unexpected and lamentable. A noble garden — one that bore convincing 
marks of an antiquity, referring to the period of Abbey lands and “ Granges ” — was 
under the direction of a very able gardener, who had every appliance at command j 
for the production of fruits, and the best parterre flowers : the soil is naturally a 
strong and rather binding loam, reposing upon a stiff, cold, and unwrought subsoil ; 
drainage had had no existence — never was once thought of. The winter of 1843 — 4 | 
was protractedly wet, the land could not absorb or carry away the superabundance! ^ 
of water, and, as the subsoil of the garden in question was little better than an§ 
impenetrable “pan,” the water reached, and actually blew up the interior of all the 
pine, melon, cucumber, and flower pits. We saw the tan and leaves floating, the pots j 
disturbed, turned on one side, and liable to the greatest injury. Fruit trees also ; 
suffered, and became sickly. By great assiduity and exertion, some portions were | 
drained ; and to make up for imperfect depth of soil, large quantities of free- working | 
turfy loam had been, and still are, brought in from a common ; but no efforts, no extrat 1 1 
labour, can prove a substitute for perfect drainage. 
The Regent’s Park, it was stated, required drainage to the depth of eight feet, i|; 
ere the soil could be duly meliorated for the establishment of the Royal Botanic j 
Garden ; and this leads to the remark, that drains opened to a certain depth act by 
the ramifications of fissures which they produce in clays and binding loams. These 
earths contract hy drying, in the manner of the clay paths in fields — wherein any 1 
person can observe cracks, which open, and continue to enlarge, during hot and I 
drying weather. As subsoil drainage carries off, at first, some water, the outer | 
surface of clay gradually contracts, more water is freed, the cracks extend inwardly, | 
and thus many feet of earth become intersected by permanent fissures, and the landf I 
is effectually relieved from stagnant water. 
Plants cannot be maintained in complete health without an adequate supply of | 
appropriate food ; hence the necessity of a renewed soil. But how are this food, and I 
the individual claims of vegetables to be discovered ? Organic Chemistry has taught j 
us that oxygen, hydrogen, carbon, are common to all vegetable bodies, and to these ; 
the fourth organic element, nitrogen, is occasionally added. These are all resolvable 
