396 Vegetable Pathology. 



hitherto impeded by mystical symbols, or rendered inaccessible 

 by learned languages, has been cleared and levelled for the 

 convenience of every traveller. 



The discoveries of our most celebrated naturalists have 

 thus become the text-book of all ages and all stations ; and 

 the earth, the air, and the sea, instead of yielding their pro- 

 ductions merely to gratify the vanity or luxury of man, have 

 afforded a more noble repast to his intellectual appetite. 



Among the various branches of natural history which have 

 long occupied the attention of mankind, none has been so 

 generally followed as botany. The attraction of flowers and 

 fruits, beautiful by their colours, tastes, and smell ; the delight 

 of rearing a living thing, which grows under our eye, and 

 developes itself from a shapeless mass to one of extreme 

 beauty and loveliness ; whose life is free from pain, and whose 

 death seals the promise of its reappearance ; the facility and 

 cheapness of procuring sustenance for its support ; and, above 

 all, the absence of all unnecessary torture and disgusting ex- 

 periments, have long made botany the favourite study of both 

 sexes ; and, consequently, there is no science more generally 

 known, and so far advanced to perfection. The physiology 

 of the vegetable kingdom has thus become a beaten track, 

 open to all, even to the lowest capacities ; and, though new 

 discoveries are daily arresting the steps of the traveller, and 

 some unnoticed plant or flower is gathered, to adorn, instruct, 

 or benefit mankind, yet the circle of discovery is more cir- 

 cumscribed in this than in any other branch of science. 



There is no department, however, in the vegetable king- 

 dom, which has been passed over with so much neglect as the 

 diseases of plants, and their medical treatment ', and which, if 

 pursued philosophically, would explain many phenomena at 

 present inexplicable. I am aware that physiologists have not 

 passed over in silence many diseases to which particular 

 plants are liable, and have described many remedies by which 

 those diseases may be alleviated or removed; and I am aware, 

 also, that the practical, as well as scientific, horticulturist, the 

 rearer of the cabbage and of the pine, have endeavoured to 

 obviate the evils in their respective avocations. But the 

 scientific treatment of the diseases of plants, by remedies 

 adapted to their construction, analogous to the diseases of ani- 

 mals which affect them, has passed without notice or enquiry. 

 This is the more extraordinary, because the analogy of ani- 

 mal and vegetable life and formation ; the growth, maturity, 

 and decay of each ; the necessity of food, light, and air ; the 

 circulation of the blood and the sap ; the distinction of sexes ; 

 the effect of climate, of cold and of heat; with an infinite 



