— 102 — 



Analysis of Lacquer:— The crude lac is filtered through a kind of 

 paper called " Yoshinogami " to remove the foreign substances and the 

 filtrate is treated as follows: — 



Water : 1-2 grams of the sample is put in an evaporating dish or a 

 watch glass and is well agitated on a water bath; it is then kept in a 

 steam oven from two to three hours and weighed. The loss thus ascer- 

 tained is taken as the water content. 



Urushiol: A small weighed quantity of absolute alcohol is heated 

 and added to the sample treated as above and the mixture is filtered 

 through filter paper of known weight. In this process, the smallest 

 possible quantity of alcohol should be used. After evaporating the spirit, 

 the filtrate is weighed and the weight is taken as the urushiol content. 



Nitrogenous Substance: The residue found on the filter paper is 

 washed with 300 cc of boiling water and the insoluble portion left on 

 the filter paper is then dried in a weighing bottle and weighed together 

 with the paper. The nitrogenous content of the crude lac is thus obtained. 



Gummy Substance: The filtrate after evaporating the water, is 

 weighed and taken as the gummy substance content. 



Different samples taken from crude lac collected from 18 years old 

 tree with a circumference of 63.6 cm and a 6-7 years old tree with a 

 circumference of 21.2 cm in Iwate Prefecture gave the following com- 

 position. 



