116 GROW YOUR OWN VEGETABLES 



most chemists or prepared in large supplies according to 

 the following directions drawn up by the Board of 

 Agriculture : 



" A paraffin barrel of forty gallons capacity will form a 

 convenient mixing vessel. The materials required for the 

 preparation of a 1 per cent, or dilute Burgundy mixture are 

 as follows : 



4 Ib. copper sulphate (Blue-stone). 



5 Ib. washing soda. 

 40 gallons water. 



" After thoroughly washing out the barrel, thirty-five 

 gallons of water should be poured into it. The copper 

 powder should then be placed in a canvas bag, which should 

 be moved about in the water until the copper is completely 

 dissolved, or, better still, should be suspended just beneath 

 the surface of the water in the barrel overnight. The wash- 

 ing soda should be dissolved in a separate vessel in the remain- 

 ing five gallons of water. The solution should then be poured 

 slowly into the copper solution, stirring the mixture 

 vigorously and continuously. If preferred the two solutions 

 may be prepared in advance and kept separately for some 

 time, but when once mixed the mixture must be used 

 immediately, for if it is allowed to stand any length of time 

 its fungicidal properties deteriorate rapidly. 



" Before using the mixture it is advisable to test it with 

 litmus paper which is obtainable from any chemist. Red 

 litmus paper should just turn blue when dipped in the 

 mixture. If it remains red, more soda solution should be 

 added till, with a fresh piece of litmus, the blue colour 

 appears. The mixture must be thoroughly stirred when 

 adding the further quantity of soda solution before being 

 re-tested. 



" When filling the spraying machine the mixture should 

 be strained through very fine wire gauze. The machines 

 should be provided with nozzles giving a fine misty spray, 



