— 100 — 



To this end, the yield of 30 trees, 21.4 cm in circumference each, 

 was fully examined and they produced an average for a single tree as 

 follows : — 



According to this table, Naka county in Kanagawa gave the largest 

 yield, followed by Kuji county in Ibaraki, and Ninohe county in Iwate 

 in order. On comparing the climates of these districts we find the 

 following facts. In Kanagawa, the climate is generally mild, especially 

 the place in which the trees were planted fronts the south, and is well 

 secured from harsh winds by oak and camphor trees. In Ibaraki, the 

 place was located in a mountainous districts and was destitute of the 

 ever-green trees common in the milder parts of that Prefecture. In 

 Iwate, place was rather cold and not well suited to the growth of the 

 tree. Thus, we can say with all probability that the production of the 

 lac is greatly influenced by the climate, the yields being less in a colder 

 region. 



V. Quality of Lac 



(A) Chemical Properties of Lac 



The freshly collected lac is termed crude lac which cannot be used for 

 lacquering. In the making of lacquer, perilla oil must first be mixed with 

 the crude lac and the operation of "Nayashi" (ripening) and "Kurome" 

 (blackening) must be carried out so that the water contained is removed. 

 The refind lacquer (Seishi-urushi) is used for coating wood, metal, etc. 



Crude lac consists of water, urushiol, a gummy substance and 

 nitrogenous matter. 



Water: — Ordinary crude lac contains of 10-30% of water. Such a 

 large content of water is unnecessary in crude lac, but 3-4%, is indispen- 



