CONFERENCE ON SPRAYING OF FEU IT TREES. 



353 



B. Paris Green. 



Formula : 



(1) Powder 



Paris green powder 1 oz. 



Water 10 gallons. 



(2) Blundell's paste (copper oxide 31 per cent., 



arsenic trioxide 59 per cent., acetic 10 per 

 cent.) 



Blundell's paste . . . . . 1 oz. 

 Water 10 gallons. 



Preparation. — Mix either powder or paste with the water, and keep in 

 constant movement, to prevent the Paris green sinking to the bottom of 

 the water. The writer has always found the addition of lime at the rate 

 of 4 oz. to the 10 gallons of benefit in stopping scorching, but Strawson 

 says this is not necessary. 



For delicate-leaved trees, such as peach, nectarine, and apricot, J oz. to 

 10 gallons is sufficient. 



Uses. — For destroying all biting insects, such as caterpillars and 

 beetles. 



Time of Application. — The same as for Arsenate of Lead. It is 

 necessary that this wash should be put on as a very fine spray, owing 

 to the scorching effect it has on foliage. It must never be used when the 

 trees are in blossom. 



C. Calcium Arsenate. 



Formula and Preparation. — Add one part milk of lime to every one 

 part of crystalline sodium arsenate, dissolved in 400-500 parts of water. 

 Or: 



Arsenate of soda (crystalline) . . . 3^ oz. 



Quicklime 3| oz. 



Water 10 gallons. 



The lime in the form of a milk is added to the dissolved arsenate. 

 Uses, dc. — The same as the previous arsenical washes. 



D. London Purple. 



Formula : 



London purple 1 oz. 



Lime 1 oz. 



Water 10 gallons. 



Uses, dc. — The same as the previous arsenical washes. 



E. Arsenite of Soda. 



Formula : 



White arsenic . . . • . . . . 2 lb. 



Sal. soda 8 lb. 



Water 2 gallons. 



Preparation. — Boil until the arsenic is dissolved (about 15 minutes) 

 and keep up to 2 gallons by adding water. Use 1 pint of this to 40 gallons 

 of water. 



vol. xxxiv. a A 



