— no 



balsam soon begins to exude. Only the stronger trees of at least 

 5 to 6 feet circumference are tapped. The trees are exhausted com- 

 pletely, which is accomplished in about 4 days; a healthy, strong tree 

 of 8 feet circumference may yield about 12 gallons balsam. 



With regard to the properties, the data given by Weigel as well 

 as those of Hooper agree on the whole with our own observations. 



Weigel 



Hooper 



Schimmel 



& Co. 



dl5° 



acid no. 



ester no. 



content of volatile 



oil 



o,977 

 73,28 

 9,66 



48,5% 



1,0124 



97,2 

 9,0 



1,0068 

 99,8 

 12,6 



39,5% 



1,0021 



96,2 

 12,3 



44% 



4i ? i% 



The balsam dissolves readily in the usual solvents such as alcohol, 

 ether, chloroform, petroleum ether, etc., only with methyl alcohol it 

 does not make a clear solution; the ammoniacal solution is slightly 

 cloudy, and gelatinises finally. 



As Weigel observes, the balsams are sometimes more, and some- 

 times less viscid, which also explains their varying content of essential 

 oil, which fluctuates between 25 and 50%. 



Weigel isolated the following constituents: 48,5% essential oil 

 (colourless; di 5 o 0,9045; «d — 8° 24'), also a resin acid (hardwickia 

 acid) and an unsaponifiable resin body (hardwickia resene). Hardwickia 

 acid represents 48,3 % of the balsam, and in the purified state is a 

 white, amorphous, odourless powder. 



To distinguish hardwickia balsam from copaiba and gurjun balsams, 

 a colour-reaction already recommended by Br ought on is, according 

 to Weigel, useful; by this method 1 drop balsam is dissolved in 

 19 drops carbon disulphide, and 1 drop each sulphuric acid and 

 nitric acid added to the solution. Whilst copaiba balsam then produces 

 a reddish-brown, and gurjun balsam an intense violet-red colour, no 

 special colour appears in the case of hardwickia balsam. 



Hooper also recommends the colour-reaction with glacial acetic 

 acid and sulphuric acid indicated by L. van Itallie and C. H. Nieuw- 

 land 1 ) for copaiba balsams, in which copaiba balsam produces a blue, 

 hardwickia balsam a brick-red coloration. 



We would still mention that the statements made both by Weigel 

 and by Hooper, according to which large quantities of the balsam 

 could be obtained in Hamburg, now no longer apply, as in spite of 

 the greatest exertion we were unable to receive even a small quantity 

 of the balsam. 



x ) Comp. Report April 1905, 25. 



