Spray Formulas. 71 



tiously and only in sufficient amount to insure thorough shicking. 

 After thorough shicking, more water can be added and stirred in 

 until it has the consistency of thick cream. When both are cold 

 pmir the lime into the diluted copper solution of required strength, 

 straining it through a fine mesh sieve or gunny cloth, and thor- 

 oughly mix. 



It is then ready for use. Considerable trouble has frequently 

 been experienced in preparing the bordeaux mixture. Care should 

 be taken that the lime is of good quality and well burned, and has 

 not been air slacked. Where small amounts of lime are slacked it is 

 advisable to use hot water. The lime should not be allowed to be- 

 come dry in slacking, neither should it become entirely submerged 

 in water. Lime slacks best when supplied with just enough water 

 to develop a large amount of heat, which renders the process active. 

 If the amount of lime is insufficient, there is danger of burning 

 tender foliage. In order to obviate this the mixture can be tested 

 with a knife blade or with ferro-cyanide of potassium (one ounce 

 to five or six ounces of water). If the amount of lime is insuffi- 

 cient, copper will be deposited on the knife blade, while a deep 

 brownish-red color will be imparted to the mixture when ferro- 

 cyanide of potassium is added. Lime should be added until neither 

 reaction occurs. A slight excess of lime, however, is desirable. 



The bordeaux mixture is best when first prepared. Stock solu- 

 tions of lime and copper can be made and mixed when required. 



SPRAY NO. 8 — BORDEAUX MIXTURE WHEN TREES ARE IN FOLIAGE. 



3 pounds of sulphate of copper. 

 6 pounds of lime. 



50 gallons of water. 



SPRAY NO. 9 — COPPER SULPHATE SOLUTION. 



(Strong solution for dormant trees.) 

 1 pound of copper sulphate. 

 25 gallons of water. 



SPRAY NO. 10 — COPPER SULPHATE FOR SUMMER SPRAY. 



4 ounces of copper sulphate. 

 50 gallons of water. 



