"236 H. G. SMITH. 



with the portion precipitated from the boiling alcohol of 

 the powdered bark. It thus appears that the whitish 

 patches on the exterior of the bark consist of a vegetable 

 wax. 



The Acid Resin. 



The ether solution from the dry alcoholic extract was 

 neutralised with alcoholic potash, the ether removed, the 

 pasty resin-salt dissolved in water, and the solution 

 extracted with ether to remove adhering substances. The 

 aqueous solution was then heated and afterwards acidified 

 with hydrochloric acid. The acid resin represented from 

 65 to 70 per cent, of the whole resin extracted. When 

 dried and powdered it was of a light drab colour, becoming 

 brown with alkalis; for this reason it could not be satis- 

 factorily titrated as the end reaction was obscured. 



The acid resin melted at 148 - 150° O., darkening at about 

 135—140° C, and was partly soluble in ammonia. The 

 acid resin evidently consists of a single substance, as is 

 indicated from the following analytical data: — 



0*1428 gram gave 0*1192 H 2 and 0*3628 gram 00 2 = 

 69*25 per cent. 0., and 9*272 per cent. H. 



C17H28O4 contains 68*88 per cent. C, and 9*452 per 

 cent. H. 



That this formula is probably the correct one is suggested 

 from the results obtained with the silver salt, prepared 

 from the neutralised resin by the addition of nitrate of 

 silver in the usual way. 



0*2048 gram silver salt gave 0*0551 gram Ag = 26*9% 

 0*1042 „ „ „ „ 0*0283 „ Ag = 27*1 % 

 Oi 7 H a7 Ag0 4 contains 26*8 per cent, silver. 



The alcoholic solution of this acid resin gives a deep green 

 colour, and deep green coloured precipitate with ferric 

 chloride. This reaction is also given with the original 



