188 RICHMOND. 



Combustions'- of the substance dried at 100° gave the following results: 



I. 0.1820 gram substance gave 0.4783 gram C0 2 and 0.1487 gram H,0. 

 II. 0.2363 gram substance gave 0.6202 gram C0 2 and 0.1823 gram ELO. 



III. 0.3261 gram substance gave 0.8569 gram C0 2 and 0.2510 gram ELO. 



IV. 0.2292 gram substance gave 0.6029 gram C0 2 and 0.1866 gram ELO. 

 V. 0.2058 gram substance gave 0.5419 gram C0 2 and 0.1700 gram H,0. 



Calculated 

 for CioHi 5 2 . 





Found per cent. 





Per cent. 



I. 



II. III. IV. 



V. 



C=71.85 



71.66 



71.58 71.66 71.72 



71.85 



H= 8.98 



9.06 



9.13 9.00 9.03 



9.17 



Cryoscopic determination of the crystalline acid in glacial acetic acid gave 

 molecular weights as follows: , 



Weight of Weight of 

 solvent. substance. 



Depression of 

 freezing point. 



Calculated 

 molecular weight 



25.9380 0.171 



0.150 



170.5 



25.9496 0.138 



0.118 



174.9 



25.4211 0.1686 



0.150 



171.5 



25.4211 0.093 



0.086 



165.0 



Average 



170.5 



The basicity was determined by titration of an alcoholic solution of the 



N 

 acid with — alcoholic potash in the presence of phenolphthalei'n. 



Milligrams of potash 

 for 1 gram of acid. 



N 

 0.5 gram required 29.5 cc. — potash 331 



N 

 0.6745 gram required 39.5 cc. — potash 332 



therefore 56.1 grams of potash would neutralize 169 grams of acid. The acid is 

 therefore monobasic. A 2 per cent alcoholic solution in a 20 cubic centimeter 

 tube gave a rotation of +2.7°. 



The residue, after complete extraction with ammonium carbonate to 

 separate the crystalline acid, was converted into its potassium salt in the 

 usual manner. Every conceivable means to induce crystallization was 

 tried, but without success. The potassim and sodium salts appear as 

 microscopic needles upon the addition of solid potash or soda to an 

 aqueous solution of the resinate, but they were too hygroscopic to allow 

 of complete purification. The alkaline earth and heavy metal salts of the 

 acid are amorphous. 



12 The elementary analyses of resin acids recorded in this paper were made by 

 Mr. Mariano Vivencio del Eosario, assistant professor of chemistry in the Philip- 

 pine Medical School. 



