MANILA COPAL. 



189 



Combustions of the noncrystalline acid, rendered as pure as possible through 

 its potassium salt, gave the following results. 



I. 0.2190 gram substance gave 0.5868 gram COs and 0.1813 gram H,0. 

 II. 0.2072 gram substance gave 0.5559 gram CO.. and 0.1681 gram H,0. 



Calcu 



ated for CooH s4 4 . 



Found per cent. 







Per cent. 



I. II. 





C = 



= 72.92 



73.01 73.13 





H: 



= 9.39 



9.19 9.07 



Molecular weight: 









Weight of solv 

 acetic acid. 



ent 



Weight of 

 substance. 



Molecular weight 

 Lowering. calculated. 



25.4961 





0.2134 



0.075 377 



25.4975 





0.1302 



0.056 353.S 



25.30.34 





0.1445 



0.061 360. 



The determination of 



th 



e basicity gave 



the following numbers : 



Milligrams of potash 

 for 1 gram of acid. 



N 

 1.0466 grams substance required 28.9 cc. — alcoholic potash 155.3 



N 

 1.0113 grams substance required 30.4 cc. — alcoholic potash 155.6 



whence 56.1 grams of potash would neutralize 361 grams. Therefore the acid 

 is monobasic. 



DISTILLATION UNDER REDUCED PRESSURE. 



One attempt at distilling the low-melting, amorphous acid was made 

 under a pressure of 3 to 5 millimeters; 75 per cent came over between 

 240° and 275° with but slight decomposition. The clear, amber-colored 

 distillate was dissolved in aqueous potash and extracted with ether which 

 removed a small amount of oily hydrocarbon. The acid recovered from 

 its potassium salt possessed the same properties as before distillation; 

 with a pressure of 1 millimeter or less it may be possible to distill 

 this acid entirely unchanged, and this offers the most promising method 

 of getting the substance sufficiently pure for a study of its constitution. 



RESIN INSOLUBLE IN ALCOHOLIC POTASH. 



% 



The semigranular mass which was thrown out of the alcoholic solution 

 of the original crude resin, upon the addition of alcoholic potash in 

 slight excess consisted of a potassium salt soluble in water, a neutral 

 residue insoluble in water, but soluble in boiling aqueous potash, and 

 a small proportion of unsaponifiable matter. 



The water soluble portion was precipitated as a white, amorphous 

 powder upon acidification with dilute hydrochloric acid. It was com- 

 pletely soluble in ethyl and amyl alcohol and aniline and slightly soluble 



