DISEASES AND THEIR CONTROL 133 
Copper carbonate -----_--__-__-_-------- 5 ounces 
Ammonia (26° Baumé) ~_---------_------ 3 pints 
Water _----- 50 gallons 
Dilute the ammonia with water to about five times its 
volume. Make a thin paste of the copper carbonate with 
a small quantity of water, and add this to the ammonia 
by constant stirring. After diluting to 50 gallons of 
water the mixture is ready for application. It should be 
used as promptly as possible because the ammonia 
evaporates rapidly. 
Potassium sulphide or liver of sulphur is sometimes 
employed in the greenhouse, especially when it is desir- 
able to avoid the discoloration of the foliage. From 
three to five ounces of potassium sulphide is used to 10 
gallons of water. 
Sulphur is sometimes applied as a dust over the plants 
for the treatment of mildews. 
