i/- 

 convenience of comparison these results are tabulated, as fol- 

 lows: 



Mean raw lac Mean for lac hard- Mean for urushic Calculated for 

 dried by heat. ened by enzyme. acid oxidized by C, 4 Hi 8 Oa 



chromic acid. 



C 75-47 70.85 71.52 71-79 



H 8.97 8.22 8.23 7-69 



N o.n o. 092 .... .... 



Ash 0.21 0.032 



15.17 20.52 20.25 20.52 



He concludes from the above analyses that the lac when 

 hardened in the usual manner takes up one atom of oxygen for 

 every molecule of urushic acid, becoming C 14 H 18 O 3 . This com- 

 pound he names Oxyurushic acid. 



More recently Bertrand 13 has worked upon Japanese lac ; 

 however he has contributed nothing of importance to the knowl- 

 edge of the alcohol soluble substance. His principal work was 

 upon the soluble ferment referred to elsewhere. 



EXPERIMENTAL INVESTIGATION. 



Three samples of lac were used in the following experiments. 

 The first and second were in glass jars bearing original Japanese 

 labels. The third was in a tin can. Apparently all were identi- 

 cal. 



The samples were all sent gratuitously to Prof. Tschirch. 

 The first by forester Shirasawa, in Tokio, and others by the 

 Rhus Company in Frankfort, a. M. to whom I here extend thanks. 



When separated according to the method of Ishimatsu they 

 gave the following results: 



Parts soluble in alcohol 72.40% 



Parts soluble in water 4.05% 



Insoluble residue 2 . 35% 



Water and volatile matter 21 .20% 



1 have found, as will appear later, that Yoshida's Urushic 

 acid may be separated by benzini into 



Benzin-soluble 78% 



Benzin-insoluble 22% 



and that the benzin soluble consists of three substances, one 

 of which is a non-volatile poison, also that the gum and enzyme 



13 Ann. chem. phys. sen XII, 1897, p. 115. 



