108 Proceedings of the Royal Irish Academfj. 



1'0124 gramme of the substance raised the boiling-point of 16 c.c. 

 chloroform by 0-61° C. Mol. wt. 270. 



CnHieOi (Brooks) requires Mol. wt. 284. 

 OasHjsOs (Anderson) requires ilol. wt. 434. 

 C24H24O6 (Cazeneuve) requires Mol. wt. 408. 

 Similarly, santalin was exhausted with ether and the ethereal extract, 

 after decolorisation by repeated washing with dilute potash, left on evapora- 

 tion a mixture of crystals, which was separated into its constituents, 

 homopterocarpin and pterocarpin, by means of carbon desulphide, a method 

 previously employed by Cazeneuve. 



In appearance, solubility, and melting-point, homopterocarpin is identical 

 with baphinitone, also a mixture of homopterocarpin with baphinitone melted 

 at the same temperature, 84° 0. as each of its constituents. 



The specific rotatory power of homopterocarpin determined by Cazeneuve 

 is too low. On redetermining it, we found that in an approximately 4 

 per cent, solution in chloroform, 



{an'\ 20=0. = - 211°. 



As would be expected, we found that baphinitone is laevorotatory, and that 

 its specific rotatory power in a 4 per cent, chloroform solution is 



[ao] 20' C. = - 211-7°, 



wliich is the same as that of homopterocarpin. 



We have therefore no hesitation in saying that homopterocarpin is a 

 constituent of barwood, and that the substance described in chemical literature 

 under the name baphinitone is homopterocarpin. 



By the gradual addition of bromine to a solution of homopterocarpin in 

 chloroform, in the presence of bright sunlight, a copious evolution of hydro- 

 bromic acid occui's, and as the reaction proceeds colourless needles separate. 

 When the chloroform was evaporated at a low temperature, and the residue 

 was dissolved in hot alcohol, the latter solution gave on cooling a precipitate 

 which consisted of colourless needles which melted at 200''C, while the parent 

 liquid gave on further concentration a yellowish amorphous soKd. The 

 analysis of the colourless, crystalline bromine derivative gave the following 

 results : — 



0-1107 gave 0-2.54.3 COo and 0-046 H,0, corresponding to C 46-.3, H 3-4. 

 0-1173 gave 0-0989 AgBr, corresponding to Br 35*9 : d-HuBraOi requires 

 C 46-1, H 3-2, Br 36-16. 



