258 MR. SADAMA ISHIMATSU ON A CHEMICAL 



The residue was treated then with hot water, and the 

 filtrate evaporated to dryness, and dried at ioo° C, and 

 put down as gum. 



The residue after gum has been dissolved out is now 

 dried on a weighed filter, and, after drying at 1 00° C, weighed 

 and put down as residue. 



Moisture and other volatile matters are, of course, de- 

 termined by the difiference. 



The examination of the amount of soluble part in alco- 

 hol after the laquor has been exposed for some 20 or 30 

 days in the sunlight, shows that the soluble portion in- 

 creased up to 72*82 per cent. This lost 25 p. c. water and 

 other volatile matter on exposure, the difference being 

 therefore 58*3 p. c, which is nearly equal to, and practically 

 the same as the analysis given in the preceding page. 

 From this we see that there is no material change in the 

 amount of soluble. 



Now a perfectly dried laquor, after being finely powdered 

 and dried at 100° C, was analyzed, and gave the following 

 result : — 



Part soluble in alcohol 1 8 '07 per ceut. 



Gum 3"63 „ 



Residue 7^"i° ;> 



ioo"o 



It occurs to me, from this analysis, that the laquor on 

 perfectly drying, alcohol as well as water has greater diffi- 

 culty to get access to the dried powder than to the undried 

 laquor, although the laquor itself may not have undergone 

 any change. 



Now urushi consists of three principal bodies : — a portion 

 soluble in alcohol ; gum ; and residue. In addition to these, 

 although it contains water and volatile matter, yet they 

 are not strictly constituents. 



