298 
Indian Forest Records. 
[VoL. i. 
increasing the adhering power of the varnish, took yet absolutely 
no direct part in the drying process. 
Examination of the Nitrogenous Residue (C). 
The albuminous residue (C), which was found to dissolve in cold 
water when it was not separated from gum, but which was precipi- 
tated from its solution on boiling, was an opaque mass of a brownish 
colour. A drying experiment similar to one performed with the 
gum, water and the Urushic acid was made with this substance also 
but with a negative result as in the case of the gum. But when the 
experiment was made with the residue which contained both this 
substance and the gum, it was found that the mixture of the residue, 
water and the Urushic acid dried almost in the same time as the 
original thitsi itself. Again when the same mixture was boiled 
before leaving it to dry, it was observed that its drying capacity was 
altogether lost. It was then naturally inferred from these experi- 
ments that as in the case of J apanese lacquer it was the action of the 
albuminous constituent as originally present in the natural varnish, 
on which depended the drying capacity of the latter, and that by 
coagulation the albumen lost its property of bringing about the 
drying of the varnish. The minimum temperature at which this 
constituent was found to coagulate is between 60-65°C. (See table 
of drying experiments below, p. 304). The coagulating point of 
the corresponding constituent of Urushi is 63°C. 
Analysis of the completely dried substance furnished the follow- 
ing results : — 
0T055 gram gave 0’2211 CO 2 and 0'1044 11,0 and 0'0023 ash. 
C = 57-15 ; H = 10-99 ; ash = 2-81. 
A determination of nitrogen by the Absolute or Dumas’ Method 
was made with this result — 
0-2120 gram gave 9-6 cc. moist nitrogen at 30°C. and 
732 mm. N = 4-73 per cent. 
Thus the percentage composition of the substance was as fol- 
lows : — 
Hydrogen .... 
Ash ..... 
Nitrogen . . . • 
Oxygen (by difference) . 
. 
.07-15 
10-99 
2-81 
4-74 
24-31 
100-00 
