TANNING MATERIALS. 



37 



(d) NONTANNINS. 



Shake 200 cc of solution as directed under extracts with such an amount of 

 wet chromed hide powder (2 (d) ) as will give the following proportions : 



Evaporate and dry 100 cc as directed under "4. Evaporation and drying." 



4. Evaporation and Drying. 



Evaporate and dry for 1C hours in a combined evaporator and dryer at from 98 

 to 100 C. ; or, after evaporating, dry for 12 hours on the bottom shelf of a 

 water oven at from 98 to 100 C. Conduct evaporation and drying in flat- 

 bottom glass dishes from 2f to 3 inches in diameter. 



5. Acidity of Liquors. 



Dilute 100 cc of liquor to 500 cc. Add 2 grams of purified animal charcoal 

 to 100 cc of the dilute liquor in a flask provided with a tube condenser. Heat 

 to boiling with frequent shaking, cool, filter, and titrate an aliquot with tenth- 

 nermal alkali. 



