54 FRUIT TREES AND THEIR ENEMIES 



is a winter wash, and although it consists largely 

 of calcium sulphide, it owes some of its important 

 properties to the presence of other sulphur compounds. 

 The proportions of the different constituents vary 

 considerably according to different recipes, but the 

 following may be taken as being the most usual — 



(22) Quicklime . . . 6 to 3 lbs. 



Sulphur .... 3 lbs. 

 Salt .... 3 lbs. 



These are mixed together, and enough water added 

 to slake the lime; while still hot, more water is added, 

 and the mixture boiled for 45 minutes ; after which it 

 is made up with water to 10 gallons. Calcium thio- 

 sulphate and pentasulphide are formed, and both 

 of these gradually change into other compounds, 

 depositing free sulphur. It is to this deposition of 

 sulphur that the wash owes its chief properties, for 

 sulphur deposited in this way is in a fine state of 

 division, and adheres strongly to the trees, the result 

 being that the wash remains on the trees a long time^ 

 and in some cases cements the eggs of insects, etc., to 

 the bark, so that they cannot hatch. The sulphur 

 and sulphide in it give it fungicidal properties, and 

 there is sufficient excess of lime to make it to a 

 certain extent a detergent agent. Whether the salt 

 in it is productive of good or not, is a debated point ; 

 if it is, the proportion of it might well be increased, 

 as also might that of the lime. 



This wash possesses the great disadvantages of 

 requiring prolonged boiling, and of rapidly changing 

 when once made, when it loses its valuable properties ; 



