MONTANA EXPERIMENT STATION. 267 



stock solution of copper sulphate, procure a barrel holdinjT^ fifty gal- 

 lons. Weigh out loo pounds of copper sulphate and after tying- it 

 in a sack suspend it so that it will hang as near the top of the barrel 

 as possible. Fill the barrel with water and in two or three days the 

 copper will be dissolved. Now remove the sack and add enough 

 water to bring the solution up again to the 50-gallon mark, previ- 

 ously made on the barrel. It will be understood, of course, that this 

 second adding of water is merely to replace the space previously oc- 

 cupied by the sack and the crystals of copper sulphate. Each gallon 

 of the solution thus made will contain two pounds of copper sul- 

 phate, and, under all ordinary conditions of temperature, there will 

 be no material recrystalization, so that the stock preparation may be 

 kept indefinitely. 



Stock lime may be prepared in the same wa}' as the copper sul- 

 phate solution. Prepare a barrel holding 50 gallons, making a 

 mark to indicate the 50-gallon point. Weigh out 100 pounds of lime, 

 place it in a barrel and slack it. When slacked, add sufficient water 

 to bring the whole mass up to 50 gallons. Each gallon of this pre- 

 paration contains, after thoroughly stirring, two pounds of lime. 



When it is desired to make Bordeaux mixture of the 50-gallon 

 formula it is only necessary to measure out three gallons of the 

 stock copper solution, and, after thoroughly stirring, 2 gallons of 

 stock lime ; dilute each to 25 gallons, mix, stir, and test as already 

 described. One test will be sufficient in this case. In other words, 

 it will not be necessary to test each lot of Bordeaux made from the 

 stock preparations, provided the first lot is perfect and no change is 

 made in the quantity of the materials used. Special care should be 

 taken to see that the lime milk is stirred thoroughly each time be- 

 fore applying. As a final precaution it will be well to keep both the 

 stock copper sulphate and the stock lime tightly covered." 



For trees in foliage use only 4 pounds of the blue stone to 50 

 gallons of water. For tender foliage like plum, cherry, and peach 

 use 3 pounds of blue stone to 50 gallons of water (Bui. 75, Oregon 

 Exp. Station). 



Ammoniacal Solution of Copper Carbonate. 



We also take this description from Farmers' Bulletin No. 38. 

 "This preparation as now generally used, contams : 



Water 45 gallons. 



Strong Aqua ammonia 3 pints. 



Copper carbonate 5 ounces. 



The copper carbonate is first made into a thin paste by adding 

 a pint and a half of water. The ammonia water is then slowly add- 

 ed, and if of the proper strength, i. e., 26 degrees, a clear, deep-blue 



