— 99 — 



(Urame-urushi) and " Tail lac " (Tome-urushi) are about the same as 

 in the other method. 



Comparing the two methods one notes that in the prime exhaustion 

 method a large quantity of better juice is obtainable in a shorter interval 

 than in the other method, although the total yield of lac is about the same 

 in both methods. Such advantages are, however, greatly offset by the 

 drawback unavoidable in the use of the prime exhaustion method that 

 more workmen are needed for tapping. 



III. Comparison of Lac produced from Large and 



Small Trees 



The average production of lac in the ordinary exhaustion method 

 is 1,273 grams from a large tree having a circumference of 63.6 cm and 

 133 grams from a smaller one having a circumference of 20.3 cm. 



In order to ascertain whether the formula that the production varies 

 with the square of radius is applicable to large trees, we may apply it to 

 the above case. The square of the radius of the large tree is 102.4 and 

 that of the smaller tree is 10.4 while the ratio of these two numbers is 

 9.84. Trees having the average circumference of 20.3 cm may well be 

 taken to represent " smaller trees " of this locality and will serve as a 

 basis for calculation. Such trees will produce 133 grams of lac, and by 

 multiplying this figure by 9.84, we obtain 1,309 grams as the calculated 

 quantity for a large tree, and this figure nearly agrees with the actual 

 quantity produced by a large tree, viz., 1,273 grams. This shows that 

 the rule of yield of lac is directly proportional to the square of the radius 

 of the trunk of the tree holds true in case of big trees. Whether, the 

 number of experiments too limited to enable us to accept this empirical 

 formula is universally true or not, but it is no doubt applicable to lac 

 trees within a certain limit of size. 



IV. Yield of Lac in Relation to Locality of Trees 



Three consecutive experiments differing in locality and surroundings 

 as above stated will serve well for comparing the yields of the trees in 

 ■different sections of the country. 



