294 
Indian Forest Records. 
[VoL. I. 
0'1245 gram HgO. C = 76‘89; H = 8'56 per ceut/ 
Urushic acid, Cj^HjgOg, requires C = 77'06; H = 8'25 
per cent. 
With lead acetate solution a greyish flaky precipitate was pro- 
duced, aud this, according to Yoshida, is a very characteristic re- 
action of lead urushate. A determination of lead in this lead pre- 
cipitate was made with the following result, ^l^he salt before an- 
alysis was thoroughly purified as in Yoshida’s experiment, that is, 
it was first washed with alcohol and then with boiling water, care- 
fully dried over a water bath, and finally over sulphuric acid in a 
desiccator till its weight was constant. 
0'1966 gram gave 0'0684 gram PbO. 
Pb = 32'27 per cent. 
Lead Urushate, (Cj^Hjy02)2Pb, requires Pb = 32'29 per cent. 
The lead salt was also burnt for carbon and hydrogen, but from the 
conditions under which the cumbustion was conducted it was be- 
lieved that the determination of hydrogen was valueless. 
O' 1550 gram gave 0'2964 COg. 
C = 52'16 per cent. 
Calculated from (Cj^Hj^02)2Pb, C = 52'42 per cent. This lead salt 
when heated to 100°C. darkened in colour to a brownish mass, 
emitting at the same time a peculiar odour. It melted at 113-115°C. 
On raising the temperature to 120°C., it was found to ignite and 
hum with a smoky flame. These observations agree very well with 
those of H. Yoshida made with the lead salt of Urushic acid. 
The experimental evidence recorded above and the properties of 
the alcoholic extract under investigation leave no room for doubt 
that it is identical with the aPoholic extract of Urushi, which H. 
Yoshida has termed Urushic acid (sp. gr. at 23*^0. = 0'9851). 
In order to show clearly that the two are identical the following 
tabular statement of their properties and chief reactions may use- 
fully be given here : — 
' On calculating the formula from the percentage of Hydrogen found, it would 
be CijHjgO, instead of But from the conditions under which the com- 
bustion was conducted I have reasons to btilieve that the combustion was a little too 
high in hydrogen. 
This and other combustions in the present investigation were carried out in the 
Chemical Laboratory of the Thomason College, Roorkee, for allowing the use of 
which my best thanks are due to iMajor E. H. de V. Atkinson, R.E., Principal of 
that institution. 
