IV.—CHINESE LACQUER. 
(Rhus vernicifera, DC.; Rhus sylvestris, 8. et Z.) 
There were lately received at Kew samples of Chinese varnish 
from Dr. Augustine Henry, Ichang. These were obtained from 
Species of Rhus growing at Patung. Specimens marked E were 
obtained from Rhus vernicifera, DC., the well-known lacquer tree 
of Japan ; while Specimens marked F were obtained, according to 
botanical specimens (No. 4893), from Rhus sylvestris, 8. et Z. 
Dr. Henry was anxious to obtain a special report on the relative 
merits of these varnishes which has been kindly furnished to this 
J 
establishment by Dr. J. K. Crow, F.C.S. 
REPORT ON SOME SAMPLES OF CHINESE LACQUER, 
by Mr. J. K. Crow, D.Sc., F.C.S. 
conditions, it took about five days to dry, while in moist air two 
days were sufficient, and in dry air a month was not long enough. 
he urushic acid was extracted by repeated treatment with cold 
absolute alcohol, but was found to represent only 37 per cent. 
against 85 per cent. in the samples analysed by Yoshida. The 
latter, however, represents his urushi as having been proc 
under official inspection, and being in the purest form obtainable. 
The fact that urushic acid by itself does not dry, as stated by 
Yoshida, was also noticed. The lead salt of this acid was prepared 
and analysed : 31-22 per cent. of Pb being obtained, a result which 
agrees fairly well with the formula (C,, H,; 0,)P, suggested by 
Yoshida. The residue after the alcoholic treatment contained of 
‘course a larger portion of diastatic matter (the active agent in 
exciting the drying or oxidation) than the original sample, but 
. ta i ture, poss yik “ 
foreign matter of a non-drying na ure, p any wiidet tise Valter is 
