6 INTRODUCTION. 



The second reason why we have included a number of half- 

 hardy, or supposed half-hardy, trees and shrubs in this Work is, 

 that we think there are few scenes in an ornamental garden 

 or pleasure-ground of greater interest to a person having any 

 knowledge of botany, however slight, than a conservative wall ; 

 that is, a wall covered with trees and shrubs, natives of foreign 

 climates, which, though they may be killed to the ground during 

 winter, yet exhibit a degree of luxuriance during the summer 

 season, which they never can display in our green-houses or 

 conservatories. Even were all such plants to be killed by frost 

 every winter, and a reserve obliged to be kept in green-houses 

 or pits to supply their place every spring, still, the splendour of 

 their appearance during the summer months, and the novelty of 

 their forms when compared with those of the spring, usually 

 grown in the open air in Britain, would far more than compen- 

 sate for the trouble incurred. When we take into consideration 

 how easy it is to have such walls flued, and to heat the borders 

 in front of them by small pipes of hot water, the capacities of a 

 conservative wall and border appear great beyond anything we 

 can at present calculate on ; and we are persuaded that, were the 

 subject of conservative walls warmly taken up by a spirited and 

 wealthy individual, something would be produced in this way, 

 as superior to our present green-houses and conservatories, as 

 these are to the orangeries and green -houses of the time of 

 Evelyn, or even of Miller. Having thus given our reasons for 

 the introduction of half-hardy species of trees and shrubs into 

 this Work, we shall next submit a few words with respect to our 

 arrangement and treatment of the hardy species. 



The general arrangement of the Arboretum et Fritticetum 

 Britannicum will be that of the natural system ; by which, 

 whether in botany, zoology, or mineralogy, those objects are 

 brought together which resemble one another in the greatest 

 number of particulars. In describing each species, we shall fol- 

 low the summary of particulars laid down in the last chapter of 

 Part II.; giving in succession the identification of the name by 

 botanists ; the synonymes, botanical and vernacular ; references 

 to published engravings ; the specific character ; the popular 

 description; the geography; the history; the poetical and le- 

 gendary allusions ; the properties and uses ; the soil and situ- 

 ation ; the propagation and culture ; the accidents and diseases 

 which the plant is liable to; the insects and parasitic plants which 

 inhabit it ; examples of its growth in the British Islands and 

 on the Continent ; and, lastly, its price in some of the principal 

 British, Continental, and American nurseries. 



In identifying the name of every species, or variety, with that 

 given to it by botanical writers, we have been guided principally 

 by our own examination of the living plant, and comparing it 



