APPENDIX. 4 2 5 



Methyl violet 0.025 gram. 



Sodium chloride i.o gram. 



Sodium sulphate 8.0 grams. 



Glycerol 30.0 grams. 



Distilled water 160.0 grams. 



Topfer's Reagent. 1 Dissolve 0.5 gram of di-methylamino- 

 azobenzene in 100 c.c. of 95 per cent alcohol. 



Tropaeolin OO. 2 Dissolve 0.05 gram of tropseolin OO in 100 

 c.c. of 50 per cent alcohol. 



Uffelmann's Reagent. 3 Add a 5 per cent solution of ferric 

 chloride to a i per cent solution of carbolic acid until an amethyst- 

 blue color is obtained. 



Topfer's method, page 413. 



2 Test for free acid, page 124. 



3 Uffelman's reaction, page 129. 



