10 The Spraying of Plants. 



The corrosive sublimate was first dissolved in the spirits, 

 and then this solution was added to the water. It was said to 

 kill the eggs as well as the insects with which it came in con- 

 tact ; and although long in use it still stands as one of the 

 most valuable agents for the destruction of some insects which 

 are not closely connected with horticultural products. It also 

 possesses 1 the power of destroying the "brown turtle [scale] 

 insect, white scaly coccus, pine bug [mealy-bug?], and red 

 spider." A decoction of tobacco was pronounced to be excel- 

 lent for the removal of aphis, thrips, and wood-lice. 



Although fungous diseases are rarely mentioned in these early 

 writings, their suppression was nevertheless attempted. John 

 Robertson, in a paper read Nov. 20, 1821, before the London 

 Horticultural Society, 2 said sulphur was the only specific remedy 

 that could be named for the treatment of mildew on peaches. 

 It should be mixed with soap-suds and then be applied by dash- 

 ing it violently against the trees by means of a rose syringe. It 

 was necessary to sprinkle all parts of the tree with the mixture 

 to be certain of success. Sulphur is to-day one of our standard 

 remedies against such mildews, and it seems that no other sub- 

 stance will soon supersede it. 



William Cobbett mentions 3 some instructions for the treat- 

 ment of the cotton blight (woolly aphis) which, if well carried 

 out, would certainly dislodge the pest. He directs that where 

 these insects are found, to wash " the place well with some- 

 thing strong, such as tobacco juice. The potato, which some 

 people look upon as so nutritious, very nearly poisons the 

 water in which it is boiled ; and an Irish gentleman once told 

 me that that w r ater would cure the cotton blight. Rubbing 

 the part with mercurial ointment will certainly do it." 



The idea that " something strong " was necessary to dislodge 

 the enemy was still, apparently, the leading thought, and 

 nearly everything that could be said to possess this desired 

 quality was probably given a chance to prove its merits at one 

 time or another. Thomas Fessenden gives 4 an interesting list 

 of a few of the materials which were supposed to possess the 



1 "The Practical American Gardener," Baltimore, 1822, 397. 



2 Trans. London Hort. Soc., Vols. i.-v. 1824, 178. 



8 Cobbett, "The English Gardener," 1829, first English edition, 289. 

 * Fessenden, "New American Gardener," sixth edition, 1832, 169. 



