31& ANALTSIS OF THE YELLOW GUM. 



The smell of the Afellow substance too is similar to that of 

 the poplar buds : and, if we cannot hence infer its perfect 

 identity with propolis, it is at least certain, that the differ- 

 ence between them is too trlflius^ to admit the supposition, 

 that bees could not employ the yeHow substance for the 

 same purpose. This conjectuVe, however, might easily be 

 verified in countries where the tree that produces it so 

 abundantly grows. 

 A cement of The resin I have just analysed entersintothe composition 

 great strength of a cement, which the natives of New Holland employ for 

 *oa(le with this • ,, , /.,-,, , , ., , r 



resin. nxmg the stone ot their hatchets to the handle, and tor se- 



curing the points of tiieir spears. This cement is capable 

 of acquiring such hardness, that the hardest substances can- 

 not separate it, or even loosen the stone fastened by it. Its 

 colour is a deep brown; and on rubbing it emits a fragrant 

 smell, which does not differ from that of the yellow resin. 

 This cement I satisfied myself of the complete identity of this cement 

 ^ ' with the yellow resin by examinii^g a sufficient quantity of 



it, taken from a hatchet brought home by Mr. Peron, and 

 which her majesty, the empress Josephine, deigned to ac- 

 cept from that navigator, as a valuable proof of the indus- 

 try of the natives of Nuyts's Land. 



A hundred parts of the brown powder furnished by the 

 cement were digestedln alcohol at 40° [sp. gr. OSl?]. Two 

 portions of this liquid added in succession were sufficient to 

 take up all the resip, that the cement contained. What re- 

 mained after the action of the alcohol was nothing but a 

 blackish gray powder, without smell or taste. The weight 

 of this residiuum was 51 parts, so that the alcohol had taken 

 up 49. 



The alcoholiq solution had a deep red colour, and was 

 exactly similar to that obtained by macerating in the same 

 menstruum the yellow resin, after it had been melted and 

 turned brown by heat. On evaporation it yielded a red 

 resin, which had all the characters of the resin of the xan- 

 thorrhcea. 



On the 51 parts not dissolved by the alcohol 1 boiled to 

 dryness a small quantity of nitric acid, which caused the re- 

 siduum to acquire a redness like that of oxide of iron, and 

 i treated this residuum with muriatic acid. After the ac» 



tion 



