— 107 — 



" Prime lac " alone was considered in the above comparison, as it forms the 

 principal product of the lac tree and is of the best quality. 



From the above table, it will be seen that the product of Kanagawa 

 is the least in water content and that of Iwate, the largest. As to the 

 content of urushiol, the Kanagawa product is richer by 2.1% than the 

 Ibaraki product while the latter in turn surpasses that of Iwate by 1.05%. 

 Further, the nitrogenous substance is the least in the Kanagawa product 

 followed in order by the Ibaraki and Iwate products ; the gummy substance 

 is comparatively small in the Iwate product. Obviously, the Kanagawa 

 product is the best, followed by that of Ibaraki and Iwate. Thus, the 

 product of warmer regions are better than those of the colder regions 

 lying in the north-eastern part of the country. 



VII. Comparison of Yield with regard to Size of Tree 



Trees that are used in the tapping of lac are in general 21 cm in 

 circumference and range in age from 6 to 10 years but among the lac 

 trees of Iwate Prefecture tried by us it must be remembered that there 

 were some large trees 60 to 85 cm in circumference. Comparing the 

 yield of lac we find that it is always advisable to collect lac when trees 

 have attained the greatest possible size, it having been established by our 

 experiments that the quantity of lac always increases in proportion to the 

 size of the trees. In comparing trees of 8 years old with those of 16 years 

 old, the former gave a production of 150 grams apiece while the latter 

 produced 1,273 grams; in other words, when the age of the tree was 

 doubled the production was increased eight-fold. 



