20 FARMERS' BULLETIN 933. 



the second pumping, put the suction hose into the spray tank and 

 the discharge hose into the storage barrels. When the spraying ma- 

 chine is used for this purpose, an old suction hose should be used, as 

 well as a discarded piece of hose for the discharge end. This should 

 be not more than 10 feet in length. The material should be run 

 through an ordinary nozzle with the disk left off. The overflow will 

 not emulsify this material. 



At present this "boiled formula" is made by the Florence Villa 

 Citrus Growers' Association and also the Tavares Association. These 

 two plants are fitted with two 300-gallon tanks and the material is 

 heated by steam. One association uses a large pressure pump with a 

 2-inch intake and a discharge of three-fourths inch. The material is 

 pumped from one tank into another and then pumped over or back 

 upon itself for about 10 minutes, and then it is barreled. This plant 

 can make 3 barrels of emulsion in about 20 minutes. The other plant 

 uses a water injector pump operated by steam. 



Owing to the high temperature of the mixture, pumps used for 

 emulsifying should have metal valves. If made of other material 

 their period of usefulness is very short. It should always be remem- 

 bered that a pressure pump must be used for emulsifying. The writer 

 has never succeeded in making an emulsion with a rotary pump. 



Difficulties that may arise in making the boiled formula are : (1) A 

 lack of sufficient heat, (2) improper pumping, or (3) an improper 

 emulsifier. In many tests the water and soap only were heated, and 

 failure to produce a perfect emulsion resulted in every instance. On 

 the other hand, when all the materials were heated together a perfect 

 emulsion was secured. The materials should be heated until a slight 

 foam or a few bubbles appear, but it is not necessary to boil for any 

 length of time. 



Some growers have failed because they attempted to stir the mate- 

 rials together with a stick, and others because they used a rotary 

 pump. Neither of these is satisfactory. 



The emulsifying agent is very important. There is no doubt that 

 potash-fishoil soap is the most satisfactory of all soaps for the mak- 

 ing of any of these emulsions. When this material is used the oil 

 very seldom separates and the resulting emulsions never become too 

 thick to be poured or handled conveniently. On the other hand, 

 when hard soaps are used which are made from caustic soda and fats 

 containing large proportions of stearin and small quantities of rosin, 

 the emulsions separate on cooling, and will cause much trouble in 

 mixing on the day after they are made. If the emulsion made from 

 any hard soap found on the market is used on the same day that it 

 is made no trouble will be experienced. The "cold-stirred" formula 

 is difficult to make with hard soaps. The writer has found it impos- 



