280 SCIENCE OF AGRICULTURE. Part II. 



circumstances ; man adopts it, and, improving on it, produces cabbages and turnips of 

 half a cwt., apples of one pound and a half, and cabbage-roses of four inches in diameter ; 

 productions which may in some respects be considered as diseased. 



1 83 1. To increase the number, improve the quality^ and increase the magnitude of par- 

 ticular parts of vegetables. It is necessary, in this case, to remove such parts of the 

 vegetable as are not wanted, as the blooms of bulbous or tuberous-rooted plants, when 

 the bulbs are to be increased, and the contrary ; the water-shoots and leaf-buds of fruit- 

 trees ; the flower-stems of tobacco ; the male flowers and barren runners of the Cucumis 

 tribe, &c. Hence the important operations of pruning, ringing, cutting off large roots, 

 and other practices for improving fruits and throwing trees into a bearing state. At 

 first sight these practices do not appear to be copied from nature ; but, independently of 

 accidents by fire, already mentioned, which both prune and manure, and of fruit-bearing 

 trees, say thorns or oaks, which, when partially blown out by the roots, or washed out 

 of the soil by torrents, always bear better afterwards, why may not the necessity that man 

 was under, in a primitive state of society, of cutting or breaking off branches of trees, to 

 form huts, fences, or fires, and the consequently vigorous shoots produced from the parts 

 where the amputation took place, or the larger fruit on that part of the tree which re- 

 mained, have given the first idea of pruning, cutting off roots, &c. ? It may be said that 

 this is not nature but art ; but man, though an improving animal, is still in a state of 

 nature, and all his practices, in every stage of civilisation, are as natural to him as those 

 of the other animals are to them. Cottages and palaces are as much natural objects as 

 the nests of birds, or the burrows of quadrupeds ; and the laws and institutions by which 

 social man is guided in his morals and politics, are not more artificial than the instinct 

 which congregates sheep and cattle in flocks and herds, and guides them in their choice 

 of pasturage and shelter. It is true that the usual acceptation of the words nature and 

 art scarcely justifies this application of them ; but we are viewing the subject in its most 

 extensive light. 



1832. To form new varieties of vegetables, as well as of flowers and useful plants of 

 every description, it is necessary to take advantage of their sexual differences, and to 

 operate in a manner analogous to crossing the breed in animals. Hence the origin of 

 new sorts of fruits, grains, legumes, and roots. Even this practice is but an imitation of 

 what takes place in nature by the agency of bees and other insects, and of the wind ; all 

 the difference is, that man operates with a particular end in view, and selects individuals 

 possessing the particular properties which he wishes to perpetuate or improve. New 

 varieties, or rather subvarieties, are formed by altering the habits of plants ; by dwarfing 

 through want of nourishment ; variegating by arenaceous soils ; giving or rather con- 

 tinuing peculiar habits when formed by nature, as in propagating from monstrosities, for 

 instance, fasciculi of shoots, weeping shoots, shoots with peculiar leaves, flowers, fruit, &c. 



1 833. To propagate and preserve from degeneracy approved varieties of vegetables, it 

 is in general necessary to have recourse to the different modes of propagating by exten- 

 sion. Thus choice apples and other tree fruits could not be perpetuated by sowing their 

 seeds, which experience has shown would produce progeny more or less different from 

 the parent, but they are preserved and multiplied by grafting ; pine-apples are propagated 

 by cuttings or suckers, choice carnations by layers, potatoes by cuttings of the tubers, &c. 

 But approved varieties of annuals are in general multiplied and preserved by selecting 

 seeds from the finest specimens and paying particular attention to supply suitable cul- 

 ture. Approved varieties of corns and legumes, no less than of other annual plants, 

 such as garden flowers, can only be with certainty preserved by propagating by cuttings 

 or layers, which is an absolute prolongation of the individual ; but as this would be too 

 tedious and laborious for the general purposes both of agriculture and gardening, all 

 that can be done is to select seeds from the best specimens. This part of culture is the 

 farthest removed from nature; yet there are, notwithstanding, examples of the fortuitous 

 graft ; of accidental layers ; and of natural cuttings, as when leaves, or detached por- 

 tions, of plants (as of the Cardamine hirsiita) drop and take root. 



1 834. The preservation of vegetables for future use is effected by destroying or render- 

 ing dormant the principle of life, and by warding off, as far as practicable, the progress 

 of^'chemical decomposition. When vegetables or fruits are gathered for use or pre- 

 servation, the air of the atmosphere which surrounds them is continually depriving them 

 of carbon, and forming the carbonic acid gas. The water they contain, by its softening 

 qualities, weakens the aflSnity of their elem.ents ; and heat produces the same effect by 

 dilating their parts, and promoting the decomposing effect both of air and water. 

 Hencet drying in the sun or in ovens, is one of the most obvious modes of preserving 

 vegetables for food, or for other economic purposes ; but not for growth, if the diying 

 processes are carried so far as to destroy the principle of life in seeds, roots, or sections 

 of the shoots of ligneous plants. Potatoes, turnips, and other esculent roots, may be 

 preserved from autumn till the following summer, by drying them in the sun, and 

 burying them in perfectly drv soil, which shall be at the same time at a temperature but 



