214 SCIENCE OF GARDENING. Part II. 



public nurseries. Many of this division are of great importance in their native countries, 

 as the indigo, sugar-cane, tea-tree, cinnamon, &c. ; the mango, durion, and other excellent 

 fruits, the palms, bamboos, &c. Even some here treated as entirely ornamental, afford 

 useful products in their own countries, as the camellia, sun-flower, &c. from the seeds of 

 which oils are expressed in China and America. The cultivation or preservation of living 

 specimens of these plants, therefore, in our green-houses and stoves, is a rational entertain- 

 ment, and also useful, as many species become in time acclimated, and some even natu- 

 ralised ; and uses may in time also be discovered for such as are now merely looked on as 

 objects of curiosity. But it is quite enough to justify much more than all the care that 

 is taken to obtain and preserve them, that they contribute to elegant enjoyment ; for what 

 is life when it does not exceed mere obedience to the animal instincts ? 



1002. With respect to the native habitations of the exotic part of the Hortus Britannicvs, 

 little can be advanced with certainty. In general it seems to appear that moist and mo- 

 derately warm climates, and irregular surfaces, are most prolific in species ; and judging 

 of the whole world from Europe, we should venture to consider half the species of plants 

 in existence as growing in soft and rather moist grounds, whether low or elevated. The 

 soil of surfaces constantly moist, or inclining to be moist, whether watered from the at- 

 mosphere or from subterraneous sources, is almost always found to be minutely divided, 

 and generally of a black vegetable or peaty nature. Immense tracts in Russia and Ame- 

 rica are of this description, and even when dry, resist evaporation better than any other. 

 In such soils, the roots of plants are generally small and finely divided, as in the heaths, 

 most bog plants, and nearly all the American shrubs. The next sort of habitation most 

 prolific in species, appears to us to be arenarious soils in temperate climates, and in pro- 

 portion to their moisture. Here the roots of plants are also small, but less so than in 

 soils of the former description. On rocky and calcareous soils the roots of plants are ge- 

 nerally strong and woody, or at least long and penetrating. In clayey habitations, ex- 

 clusive of the alluvial depositions of rivers, few plants are found, and these generally 

 grasses, or strong fibrous-rooted herbaceous plants, or tap-rooted trees. Such at least is 

 the amount of our generalisations ; but as our observation has been limited to Europe, and 

 does not even extend to the whole of it, those who have visited Africa and Asia are much 

 more capable of illustrating the subject. One conclusion we think the cultivator is fully 

 entitled to draw, that the greater number of plants, native or foreign, will thrive best in 

 light soil, such as a mixture of soft black vegetable mould or peat and fine sand kept 

 moderately moist ; and that on receiving unknown plants or seeds, of the native sites of 

 which he is ignorant, he will err on the safe side by placing them in such soils rather 

 than in any other ; avoiding, most of all, clayey and highly manured soils, as only fit 

 for certain kinds of plants constitutionally robust, or suited to become monstrous by 

 culture. 



Chap. XI. 

 Origin of Culture, as derived from the Study of Vegetables. 



1003. Agriculture and gardening are the two arts which embrace the whole business of 

 cultivating vegetables, for whatever purpose they are applied by civilised man, and in this 

 respect their fundamental principles are the same ; they are all indicated by nature, and 

 explained by vegetable chemistry and physiology. 



1004. The object of vegetable culture is either to increase the number of plants ; to in- 

 crease their number and retain their native qualities ; to increase their number and im- 

 prove their qualities ; to increase their magnitude ; to increase their number, improve the 

 quality, and increase the magnitude of particular parts of the vegetable ; to form new varieties 

 for the furtherance of all or any of the above purposes ; to propagate and preserve from 

 degenerating approved varieties of vegetables ; and to preserve vegetables for future use. 



The first step, for all these objects in common, is to procure the desired plant, either by removing it in 

 an entire state from its native site, and planting it in an appropriate situation ; or by gathering and sow- 

 ing its seeds ; or by propagating from a part of the plant. Hence the general origin both of agriculture and 

 gardening, and of all the different modes of propagation, transplanting, and collecting seeds. 



The next step is to secure the plants to be cultivated from the depredations of animals, or unsuitable 

 weather, either by surrounding them with an adequate barrier where they are growing fortuitously, or by 

 removing them to a spot already protected. Hence the origin of fences and enclosures, and plant habita- 

 tions. 



A third step common to all the above objects of culture is to remove from the vicinity of the plant to be 

 cultivated, or from the plant itself, all other plants, or animals, or objects likely to impede its progress. 

 Hence the origin of weeding, thinning, destroying insects, and curing diseases. 



1005. To increase the number and retain the native qualities of vegetables, it is necessary 

 to imitate, as exactly as circumstances will admit, their native habitation, in respect to 

 soil, climate, mode of watering, light, &c. If the habitation is in any way ameliorated, 

 the qualities of the plant will be altered, and its parts enlarged, which is not desired. 



