254 MR, SADAMA ISHIMATSU ON A CHEMICAL 



obtained from Kuyemon Nakamuraya, in Tokio, a large 

 urushi-keeper. 



It is a milky juice of a pale grey colour ; and the Japanese 

 call it " ash-colour," from its colour resembling so much 

 that of ash. It gives out a certain kind of volatile acid, 

 poisonous in its property, and some persons are seriously 

 attacked by it, producing great swellings on the face 

 especially, and even the whole body where the acid 

 comes in contact. During my examination in the labora- 

 tory, one day one of the apparatus-keepers came in and 

 wlas violently attacked by it, producing ugly swellings all 

 over his face. He told me at the time it was exceedingly 

 itchy, and by using the solution of acetate of lead, chloride 

 of potash, and carbonate of soda, was said, to have recovered 

 from this suffering within a week. 



The poison that is evolved from urushi acts only on 

 certain persons. I had to work with it for many days, yet 

 never had any attack of the kind nor felt any uneasiness 

 by it. 



Urushi being heavier than water, sinks to the bottom; 

 and under this condition oxidation does not take place; so 

 the colour remains unaltered, and the mass remains soft 

 as long as it may be kept in this way. 



It has a sweetish characteristic smell and has an irri- 

 tating taste. It burns with a very luminous flame, evolv- 

 ing dense black smoke like oil of turpentine. It is soluble 

 in absolute alcohol, ether, benzol, &c. to a great extent, 

 leaving behind a blackish grey residue, in which gum was 

 found. 



Urushi, on exposure to the atmosphere, rapidly loses its 

 weight, and at the same time blackens on its surface, 

 forming in time a hard crust — although this loss is dif- 

 ferent in different specimens, varying in the specimens I 

 have examined from 25 to 35 per cent. 



