208 TREE WOUNDS AND DISEASES 



the proportion of an ounce to three gallons of 

 water is a valuable fungicide, in the case of 

 both forest and fruit trees. In severe attacks 

 of either fungus or aphis the proportion of 

 potassium sulphide may be slightly increased. 

 Copper sulphate, which enters into the com- 

 position of the now well-known and valuable 

 Bordeaux mixture, is an excellent fungicide. 

 It may be used in the proportion of three- 

 quarters of a pound weight to ten gallons of 

 water. The Bordeaux mixture contains, in 

 addition, half a pound weight of fresh lime. 

 Woburn wash, which also contains copper 

 sulphate, is a valuable remedy for fungus 

 attacks. 



Great care is necessary in compounding 

 these fungicides, too small a quantity of the 

 more powerful ingredients rendering the 

 mixture valueless for the purpose intended, 

 while too great may do irreparable damage to 

 bark or foliage. When small quantities only 

 are required, it is preferable to purchase from 

 some of the firms who make the preparation 

 of such a specialty. 



Insecticides. These are many and vary greatly 



