1X2 JOURNAL OF AGRICULTURE OF P. R. 



a half of each stock if they are double strength. The concentrated 

 solutions should not be mixed directly. 



It is essential that all the copper be neutralized, since free cop- 

 l^er will cause serious burning. This fonnula ordinarily provides 

 a wide margin of safety, but a weak solution of ferrocyanide of po- 

 tassium can be used for testing where there is any doubt. A black 

 color, showing when a few drops are placed in a saucerful of the 

 Bordeaux mixture to be tested, indicates free copper and nion- litrio 

 must be added. 



BORDEAUX PASTE. 



Commercial Bordeaux paste or powder can be used by adding 

 sufficient water to make up a paste of the necessary consistency, 

 or it can be prepared as follows: 



One pound of cof)per sulphate is dissolved in one gallon of water. 

 Two pounds of live lime are slaked in one-half gallon of water. The 

 two mixed together give a satisfactory compound. This material 

 deteriorates rapidly and should be made up only as needed. Stock 

 solutions for Bordeaux mixture can be conveniently used by tak- 

 ing proper amounts of each. 



LIME-SULPHUR.^ 



Unslaked lime 50 pounds. 



Sulphur 100 pounds. 



Water 50-60 gallons. 



Any of the several form of sulphur, sulphur flours, flowers of 

 sulphur, or powdered commercial sulphur, will be found to yield 

 satisfactory results. The only requirement in this connection is 

 pure sulphur (at least 99 per cent), no matter what its form. 



This combination has been found to give most uniform results. 

 It can, of course, be modified to any extent desirable as long as the 

 ratio of 1-2-1 between lime, sulphur, and water is maintained. In 

 the case of the water, enough should be used to allow for evapora- 

 tion or else more added from time to time so that there will be ap- 

 proximately fifty gallons of product at the finish. Using more than 

 fifty gallons of water will give a concentrate of less density, but 

 one containing less sediment. 



Equipment. — A great variety of kettles or boilers can be obtained 

 for the preparation of lime-sulphur and in any size, adapted to 

 the need of each grower. The large iron kettles used in the old open- 



' Partial reprint of Cirriilar l.T, Insular Experiment Staticin, the English edtiion of 

 ■which is exhausted. 



