346 



Ether Extract from the Resin Acids. 



The ether from tlie 25 grams of rrsiii, after tlie acids had been removed, 

 was evaporated to dryness, and the resi(kie heated on tlie water bath till constant. 

 It weighed 5-86 grams, equal to 24-44 P^r cent. It was a soft, yellowish resin. 

 and had a very bitter taste. It was laevo-rotatory, and 0-7293 gram dissolved 

 in ID c.c. alcohol in 100 nim.tiibc had a rotation of 4-4° to the left. The specific 

 rotation was, therefore, {(i]u — 60-3°. It thus agrees in tlie direction of rotation 

 with the acid of low melting point. 



Nitrogenous Substances. 



The residue, after the removal of the resins, was treated with alcohol for 

 two da3's to remove possible traces of resinous bodies. When filtered off it was 

 a swollen mass, light drab in colour, and when air-dried had shrunk considerably 

 in bulk. It was powdered, and treated with water to remove any remaining 

 gum and similar substances. When again dried it was powdered and finely sieved 

 to remove a few particles of wood, &c. The powder thus obtained weighed 3-5 

 grams, or 0-51 per cent, of the latex. It was quite insoluble in water, alcohol, and 

 similar solvents, and also in dilute acids, but it was mostly soluble in alkalis, even 

 in the cold, and became yellow when heated with potash. When heated with 

 soda-lime, ammonia was readily evolved. The amount of nitrogen present was 

 determined by Kjeldahl's method, and the ammonia from i gram neutralised 

 2-1 c.c. HoSO, = 2-94 per cent, nitrogen in the i)owder. It is thus apparent 

 that the latex contained albuminous substances or other nitrogenous bodies, and 

 it would be interesting to determine their identity. The severe treatment to which 

 the latex had been subjected by continued boiling had evidently altered these 

 bodies considerably, and destroyed the en/.ymes. Only the merest trace of man- 

 ganese could be detected in the ash, so that that substance had been precipitated 

 with the gum from the aqueous portion of the latex. 



From the foregoing results the general composition of the latex ol Arnitcana 

 Cunninghamii may be stated as follows: — 

 Volatile oil ... 



Free acids (calculated as acetic) . . . 

 Gum 

 Resin 



Nitrogenous substances, tie. 

 Woody residue 

 Water and nndrici-niincd ronsti- 



lucnts by difference ... . , .)9'956 



3- 800 



l)er 



cent 



0-I3-I 







8-000 







.7-000 







0-510 







0-600 







TOO- 000 



