Proceedings of Societies. 
[April, 
32 + 
Manchester Literary and Philosophical Society, February 
18. — J. P. Joule, D.C.L., LL.D., F.R.S., &c., President, in the 
chair. 
Professor Roscoe, LL.D., FoR.S., communicated a paper by 
Sadamu Ishimatsu, “ On a Chemical Investigation of Japanese 
Lacquer, or ‘ Urushi.’ ” During a few months last year the 
author had the opportunity of examining roughly into the nature 
of “ Urushi,” in the Laboratory of Tokio University. The spe- 
cimen of lacquer which he had under his examination was 
obtained from Kuyemon Nakamuraya, in Tokio, a large lacquer 
merchant. It is a milky juice of pale grey colour, and gives out 
a certain kind of poisonous volatile gas. Some persons are 
terribly attacked by this poison, producing a great swelling where 
the acid comes in contact. During the author’s examination in 
the laboratory one of the apparatus keepers was terribly attacked 
by this gas, producing ugly swellings all over the face. By using 
the solution of chloride of sodium, carbonate of soda, acetate of 
lead, &c., he was said to have recovered within a week. This 
poison, however, adts only on certain persons, for the author 
while working with it never felt any uneasiness from it. The 
blackening of lacquer in air is by many supposed to be due to 
the combined acftion of light and air, but from the following ex- 
periments this seems to be erroneous: — 1. A square box was 
made which had a well-fitting sliding door, and the inside of 
which was made perfectly black, so that pracftically no light was 
permitted to enter. In it was placed a small quantity of lacquer 
at dark, and the door closely shut. On looking at it the next 
morning it was observed that the lacquer had turned perfectly 
black, proving that it is not light that blackens the lacquer. 
2. The bottle in which the specimen of lacquer was kept for 
more than three months was exposed to the incident light of the 
laboratory. The surface of the lacquer was turned perfectly 
black, forming a wall as it were; while those portions which were 
in contadl with the sides of the bottle, which receive as much 
light as if there were not any glass sides before it, were not at 
all blackened. This phenomenon proves that the blackening in 
the atmosphere is in all probability due to the oxygen of the air, 
but not to light alone, nor to the combined adlion of light and 
air. The examination showed that the “ Urushi ” consists of 
three principal constituents : (1) a resinous part soluble in alcohol, 
(2) gum, and (3) residue. The resinous part soluble in alcohol 
seems to be the principal portion : it has a smell like ordinary 
lacquer, but it never dries as the original does. It is brownish 
black, and slightly sticky to the touch. When treated v/ith pot- 
ash solution it forms a bluish black precipitate, but nothing is 
obtained on addition of sulphuric acid to the filtrate. When 
boiled with hydrochloric acid the resin is transformed into a sub- 
stance elastic while hot, something like the mass obtained when 
heated sulphur is dropped into cold water. When boiled with 
