Page 63, omit at end of (d) all relating to factors and insert: 

 The weight of hydrazone X 0.516 + 0.0104 -r- weight of sample used = percent- 

 age furfurol. 



Furfurol X 1.84 = pentosans. 

 Pentosans -r- 0. 88 = pentoses. 

 Furfurol X 1.65 = xylan. 

 Furfurol X 2.03 = araban. 



DETERMINATION OF PENTOSANS BY MEANS OF PHLOROGLUCIN. 



On page 63, at the conclusion of (d) add the following: (dj) Three grams 

 of the material are brought into a ten-ounce flask, together with 100 cc of 12 per 

 cent hydrochloric acid (sp. gr. 1.06) and several pieces of recently heated pumice 

 stone. The flask, placed upon wire-gauze, is connected with a Liebig condenser, 

 and heat applied, rather gently at first, using a gauze top to distribute the flame, 

 and so regulated as to distill over 30 cc in about ten minutes. The 30 cc driven 

 over are replaced by a like quantity of the dilute acid by means of a separatory 

 funnel, and the process continued as long as the distillate gives a pronounced 

 reaction with aniline acetate on filter paper. To the completed distillate is grad- 

 ually added a quantity of pholoroglucin dissolved in 12 per cent hydrochloric 

 acid, and the resulting mixture thoroughly stirred. The amount of phloroglucin 

 used should be about double that of the furfurol expected. The solution first 

 turns yellow, then green ; and very soon an amorphous greenish precipitate ap- 

 pears, which grows rapidly darker, till it finally becomes almost black. The solu- 

 tion is made up to 500 cc with 12 per cent hydrochloric acid, and allowed to stand 

 over night. In case there is very little furfurol in the substance tested, and the 

 resulting distillate consequently small, it is best to add sufficient 12 per cent 

 hydrochloric acid to the distillate before adding the phloroglucin solution, so 

 that, upon the addition of the latter solution, the resulting mixture will contain 

 approximately 500 cc. 



The amorphous black precipitate is filtered into a tared Gooch crucible through 

 an asbestus felt, washed with 100 cc of water, dried to constant weight by heat- 

 ing from three to four hours at 100, cooled and weighed, the increase in weight 

 being reckoned as phloroglucid. To calculate the furfurol from the phloroglu- 

 cid, use the following table : 



Weight of phloroglucid : 



1.820 



1.839 



1.856 



1.871 



1.884 



1.895 



1.904 V == furfurol. 



1.911 



1.916 



1.919 



1.920 



1.927 



1.930^ 



METHODS FOR THE ANALYSIS OF FERMENTED AND DISTILLED 



LIQUORS. 

 Add on page 77, after 18 : 



"19. DETERMINATION OF FUSEL OIL. 



' ' The apparatus recommended for this determination is Brom well's modifica- 

 tion of Roese's fusel-oil apparatus. 



