// 







-' HE 



VE^S'TY 



of raw lac. In China the yield is said to be much less, in some 

 districts not more than 10 Grammes. 



Yoshida 8 states that Ki-Urushi is never sent to the market 

 in the form in which it is obtained from the tree but is usually 

 mixed with about 40% of "Mokuyiki" (wood juice) which close- 

 ly resembles Ki-Urushi but contains a much larger proportion 

 of gum and about j4 as niuch substance soluble in alcohol. It 

 is doubtless an impure form of urushi juice. Before 

 the raw lac is ready for use it must be strained 

 through cotton or linen cloth to remove pieces of bark and 

 foreign particles. It is then stirred in a shallow wooden 

 pail to remove the grain and give it a uniform consistence. 

 The varnish makers sometimes add linseed oil ; also from i 10% 

 of perilla oil is sometimes added. The lac mixed with 1/5 perilla 

 oil is sometimes used for coating umbrellas and water proofs. 

 Various colors are made by adding pigments. The red, so fre- 

 quently used for a part of Japanese decorations is formed by 

 mixing 70 parts Ki-Urushi, 20 parts linseed oil and 10 parts ver- 

 million. One per cent of gamboge either in powder or in solution 

 is sometimes added. The best gloss black is formed by mixing 

 purified lac with acetate of iron, formed by macerating nails or 

 iron filings in vinegar or rice beer, and heating or exposing to 

 the action of the sun. The lac thus prepared contains from 0.5 

 to 2% of iron. Other substances are sometimes added as indigo, 

 iron oxide, lead oxide, charcoal, and for decorative purposes, gold 

 and silver dust, gold, silver, and tin foil are used. 



The only substance used by the Japanese to thin the lac is 

 camphor, which is powdered and mixed with the lac. Rein ob- 

 served that when water is mixed with lac that it thickens and be- 

 comes jelly-like, and if applied to wood dries very rapidly. 



If the lac is allowed to harden in a dry atmosphere it has 

 a dull appearance. Hence it must be dried in the presence of 

 moisture which is necessary to ensure the best action of the 

 enzyme. Therefore the articles coated with the lac are placed 

 in a room and wet cloths are hung on the wall or about the lac- 

 quered articles. A temperature of from 20 to 30 is best adapted 

 for this process. 



8 Jour. Chem. Soc., 18839. 472. 



