I. 



Per cent. 

 4.0 



II. 

 Per cent. 



e 75.0 



S0.0 



6.0 



5.0 



12.0 



12.0 



2.0 

 1.0 



2.0 

 1.0 



MANILA COPAL. 183 



designated as soft, geographical origin not stated, consisted of nut-sized lumps 

 of a yellowish-red color and completely soluble in alcohol. The second specimen, 

 designated as hard, was from the Celebes and consisted of larger lumps than the 

 first, clear yellow in color, and only partially soluble in alcohol. Both samples 

 possessed practically analogous physical properties, but varied in their chemical 

 constants as follows : 



I. II. 



Acid value 134 118 



Saponification value 190 165 



By applying Tschirch's method of the proximate analyses of resinous substances, 

 which consists in dissolving the crude resin in ether and extracting successively 

 with 1 per cent of ammonium, sodium, and potassium carbonates and subjecting 

 the residue to steam distillation, they obtained the following results for the two 

 samples in question : 



c , , , . ,. , , | Soluble in ammonium carbonate 



Soluble in sodium carbonate < 



I Insoluble m ammonium carbonate 



fEtherial oil 



Residue 

 Insoluble in sodium carbonate -J yKTnip 



Undetermined 



100.0 100.0 



From the above tabulated data it is noted that the hard and soft marked 

 varieties of Manila copal have the same composition within the limits of experi- 

 mental error of analysis for this class of substances, with the one exception that 

 the soft, alcohol-soluble variety contained a small proportion (4 per cent) of acids 

 which were soluble in a dilute solution of ammonium carbonate. 



Aside from numerous reports on the physical and chemical constants 

 of Manila copal which have appeared throughout the literature and in no 

 instance of which are any botanical identifications given, the work of 

 Tschirch and Koch constitutes all that is recorded concerning the con- 

 stituents of "Manila copal." 



EXPERIMENTAL. 



The two marked varieties of "Manila copal,'"' namely, recent surface 

 and mined resin, were obtained from the Manila Trading and Supply 

 Company, the largest local graders and exporters of this commodity. The 

 samples were taken directly from sacks of ungraded provincial shipments 

 of known source. 



The surface resin came from Davao, Mindanao, and consisted of pale, lemon- 

 yellow semitransparent pieces of nut and thumb size, graded as "sorts." It 

 was. incompletely soluble in absolute alcohol, leaving a grayish, gelatinous, neutral 

 residue which dried to a brittle resin. The crude resin was difficult to pulverize 

 and possessed no well-defined melting point, but became somewhat softened and 

 sticky at 100°. 



The acid value, determined by dissolving approximately 1 gram of the 

 coarsely powdered resin in 50 cubic centimeters of absolute alcohol and 



