( 293 j 



On treating Iupeol with acetic anhydride and sodium acetate ai 

 170", they did not obtain Iupeol acetate, but lupeylene, and they 

 argue that the acetate cannot be obtained by the ordinary methods 



owing to tlie Iupeol losing water so readily. 



But some time ago (loc. rit.) I obtained with Dr. v. n. Linden 

 an acetate, by acetylating Iupeol; whilst Dr. Cohen also prepared 

 this ester and studied several of its reactions. 



It, therefore, did not seem to me superfluous to repeat the expe- 

 riments of these French chemists, and to again prepare and analyse 

 the Iupeol acetate, so as to make sure that this substance really 

 exists; and that Dr. Cohen, who did not analyse it, because the 

 properties coincided with those of my preparation, and because a 

 mixture of his acetate with Iupeol exhibited a considerable lowering 

 of the melting point, was really in possession of the substance. 



In order to observe readily an eventual separation of water, and 

 to see and weigh the same, 1, first of all, heated Iupeol for many 

 hours in one of the limbs of a reverted U vacuum tube placed in 

 an oilbath at 190°, whilst the other limb was cooled in a Weinhold's 

 glass containing liquetied ammonia. In the limb containing the Iupeol 

 a sublimate of beautiful crystals had deposited above the oil surface 

 whilst a slight deposit had also formed in the cooled limb. 



The weight of the Iupeol was 0.5403 gram. 



The deposit in the cooled limb weighed 0.0065 gram. 



On heating the same at 100° there remained 0.0046 gram. 



Therefore only traces of water could have been present in the 

 cooled limb. 



The sublimate in the heated limb melted at 212° — 213°. 



In another experiment, 1.0806 gram of Iupeol was weighed in a 

 glass boat and placed in a horizontal tube which could be heated 

 in an airbath. The tube was connected to a reservoir with sulphuric 

 acid and the whole apparatus was evacuated by means of a water- 

 airpump. First I heated the apparatus for ten hours at 140° — 160°; 

 the loss of weight amounted only to 0.0066 gram, but it must be 

 observed, however, that a sublimate had formed in the tube just 

 above the boat. Then the substance was heated in the same manner 

 for six hours at 190°— 200'. The total loss in weight then amounted 

 to 0.041 gram, but as the sublimate weighed 0.039 gram it was in 

 reality only 0.002 gram. A separation of water, which would have 

 amounted to 0.040 gram, was therefore again out of the question. 



The residue of the two experiments, after being recrystallised from 



