184 RICHMOND. 



titrating directly with seminormal alcoholic potash in the presence of 

 phenolphthalein gave the following numbers for a mixed sample: 



Milligrams of potash 

 for 1 gram of resiu. 



N 

 0.8704 gram rquired 4 cc. — potash 128.6 



N 

 0.9834 gram required 4.5 cc. — potash 128.1 



Z 



0.9762 gram required 4.45 cc. — potash 127.6 



N 

 1.1934 grams required 5.45 cc. -i- potash 128.1 



Z 



Average 128.1 



Individual pieces gave direct acid values varying from 120 to 130. 

 Saponification values were determined by dissolving approximately 1 

 gram of the resin in 50 cubic centimeters of absolute alcohol, then adding 

 25 cubic centimeters of seminormal alcoholic potash and heating on a 

 steam bath with a reflux condenser for one hour and titrating the 

 excess of potash with seminormal alcoholic hydrochloric acid. The fol- 

 lowing numbers were obtained. 



Milligrams of potash 

 for 1 gram of resin. 



N 

 1.0452 grams required 6.66 cc. — potash 178.4 



N 

 1.1074 grams required 7.0 cc. — potash 176.9 



N 

 1.0522 grams required 6.66 cc. — potash 177.2 



0.9232 gram required 5.88 cc. — potash 178.3 



Z 



Average 177.8 



Somewhat higher saponification values were obtained by digesting 

 with an excess of alcoholic potash for longer periods, and individual 

 pieces of the resin showed variations of 20 units in the total amount of 

 potash required when digested for a given period. 



The mineral resin. — The second variety was from the Island of Palawan. It 

 consisted of brownish-yellow, irregular masses, varying from those of the first 

 size to large, angular pieces of 1 to 2 kilos in weight. It was easily ground to a 

 fine powder which was completely soluble in alcohol. Its direct acid and saponifi- 

 cation numbers, taken from an average of four separate determinations of a mined 

 sample, were 112.5 and 150.6, respectively. Individual pieces of the mined resin 

 gave direct acid numbers ranging from 100 to 120 and complete saponification 

 numbers from 140 to 160. 



For the purpose of further comparison, four samples of resin of the 

 following descriptions were selected from a sack of unsorted copal : 



1. Very brittle, nearly white, bold piece. 



2. Very brittle, dark brown, bold piece. 



3. Very pliable, nearly white, irregular mass. 



4. Very pliable, dark brown, irregular mass. 



