5o6 



Journal of Agricultural Research 



Vol. X, No. 10 



Quassia wood is difficult material to get into a fine state of commi- 

 nution. The coarser subdivision can be obtained by shredding and the 

 next smaller division can be effected by means of burr mills. The 

 fine powders, however, can only be secured by continued action of a 

 pebble mill or a chaser mill. The expense of reducing the wood to fine 

 powder would therefore be too great to make its use in that form eco- 

 nomical. When the cost of grinding is taken into consideration, it seems 

 that the most economical form in which to use quassia wood is that 



corresponding to No. 5 

 to 7 in Table III. This 

 material is about the 

 size of coarse sawdust. 



{d) Influence of Quan- 

 tity OF Water Used 



In making spray so- 

 lutions from quassia 

 chips it is a question 

 whether it is more ex- 

 pedient to soak the 

 necessary quantity of 

 chips in the entire 

 quantity of water or to 

 soak them in a small 

 quantity of water and 

 later dilute the filtrate 

 to the quantity of solu- 

 tion wanted. The lat- 

 ter method is, as a rule, 

 the more convenient 

 one in large operations, 

 because the chips can 

 be soaked in a suitable 

 barrel and later the 

 dilution can be made in the spray tank. On the other hand, the first 

 method, owing to the slight solubility of quassiin in water, would appear 

 to insure the more thorough extraction. This method, however, involves 

 the use of a soaking tank large enough to hold the entire volume of spray 

 solution. In the following experiment an attempt was made to deter- 

 mine the effect of the volume of water used on the total quantity of 

 extract dissolved from the chips. 



Four portions of 10 gm. each of medium-sized chips were macerated 

 for 24 hours, in 250, 1,000, 2,000, and 3,000 c.c. of distilled water, 

 respectively. After filtering, 200 c.c. of each filtrate were evaporated, 



/ 3 3 '^ ^ S 7 <S 3 /O // /^ 



Fio. 3. — Graph showing the influence of the state of fineness of the 

 quassia chips upon the percentage of extract obtained when extract- 

 ing 10 gm. with 500 c.c. of water for 24 hours. 



