12 The Spraying of Plants. 



Dr. William Kenrick l speaks of aloes and cayenne pepper, 

 among other materials, as being effective in the treatment of 

 aphis, but their use never became very general. He also gives 2 

 a formula for the destruction of a white, mealy insect : 



Quicklime 2 peck. 



Flowers of sulphur pound. 



Lampblack I " 



Mix all in as much boiling water as will make a thick paste, 

 and apply warm. The lime and the sulphur are probably the 

 most active portions of the mixture. Although lampblack is 

 here mixed with them, these two substances, when used to- 

 gether in water, already formed one of the most important and 

 valuable remedies in use against the various mildews which 

 attack plants. The same writer gives 3 the following formula, 

 in which sulphur and quicklime are recommended for checking 

 mildew on grapes : 



Sulphur \ pint. 



Quicklime piece size of the fist. 



Water (boiling) 2 gallons. 



When cool, dilute with cold water, and allow the solid mate- 

 rial to settle. Then draw off the clear liquid, and pour it into 

 a barrel. The barrel is then filled with water, and the mixture 

 is ready for use. A modification of this formula eventually 

 came to be a standard preparation for the treatment of mil- 

 dews; but during this period the substances were used in 

 varying proportions, and generally other ingredients were 

 mixed with them. 



John Mearns made a composition, which was suggested to 

 him by Thomas Andrew Knight, at that time president of the 

 London Horticultural Society. 4 In a paper read in 1835, he 

 gave directions for making this preparation : 



Strongest farmyard drainage 1 gallon. 



Soft soap 1 pound. 



Flowers of brimstone " 



1 William Kenrick, " The New American Orchardist," 1833. Introduction, 

 xxxiii. 



2 Ibid, xxx vi. 3 /j^. 328. 



* Trans. London Hort. Soc. second series, 1842, Vol. ii. 39. 



