130 



The resiu, caustic soda, and flsli oil are placed iu a suitable \'essel 

 and the 15 gallons of water is added all atone time. The heat is then 

 ai)i)lied, and just as soon as the mixture comes to a boil, which will in 

 a measure depend upon the strength of the fire, the preparation becomes 

 clear brown, indicating that it is ready to be removed from the fire. 

 When allowed to cool this mixture is of a yellowish color and some- 

 what opaque. As already indicated, however, it readily mixes with 

 cold Avater, forming a brownish, clear solution entirely free from flaky 

 masses of soap. 



For use in the greenhouse in combating red spider on violets, climb- 

 ing asj)aragus, and roses, we dilute the stock jjreparation at the rate of 

 1 to 3, that is, 1 part of stock solution to 3 parts of water. This is 

 rather strong, and perhaps for all ordinary purposes 1 to 4 will have 

 sufficient strength. The concentrated wash made up in accordance 

 with the foregoing formula wdl cost approximately 4| cents per gallon, 

 not counting the labor, which will not exceed 10 cents for the 15 gallons 

 of wash, making the total cost of the stock preparation approximately 

 5J cents per gallon. Prepared by the old formula the total cost will 

 be not less than Gi cents a gallon for the concentrated wash, estimating 

 the cost of labor at 30 cents. These figures are valuable only in a com- 

 parative way, as the actual cost of the washes could probably be reduced 

 one-third by making them in large quantities and buying the ingredients 

 at wholesale prices. As a matter of fact, the 98 per cent caustic soda can 

 be obtained in 400-pound barrels for 0.^ cents per pound, or in broken 

 lots for 8^ cents per pound. The 70 per cent caustic soda costs about 

 4^ cents in GOO-pound drums and 7 cents per pound in small quantities. 

 The granulated soda is much more convenient to handle than the other 

 form, and furthermore, it requires no preliminary treatment, such as 

 breaking up, dissolving in water, etc. 



As already indicated, we have used the resin wash in combating red 

 spider on violets and have found it very efficient. It seems to me that 

 the compound is worthy of trial in greenhouses as a remedy for sooty 

 mold, red spider, and plant lice. 



(6) Resin-icash-Jcerosene emulsion. — It has been found that a thick 

 emulsion can be made by churning together while cold equal parts 

 of the imperfect resin wash made with an excess of caustic soda and 

 kerosene. This emulsion, however, is not stable, probably owing to 

 the fact that the proper proportions have not been worked out. The 

 emulsion may be diluted to almost any strength and in this condition 

 is more stable than when not diluted. A more stable and iu fact a 

 better emulsion may be made by using the kerosene and the diluted 

 resin wash in strengths ranging from 1 to 5 to 1 to 20. These emul- 

 sions are milky white and show upon standing very little free oil. Not 

 enough experiments have been made, however, to warrant any definite 

 statements in regard to the preparation. The emulsions were suggested 

 to Mr. Marlatt, who has already given his experience with them in 

 treating the pear-tree Psylla. 



