APPENDIX I. 

 REAGENTS. 



The reagents mentioned in the text, unless otherwise 

 stated, are solutions of the following concentration or of sub- 

 stances which must show the following standard of purity : 

 Acetic Acid, containing 30 per cent, of acetic acid. 

 Alcohol. Must be colorless and leave no residue on evapora- 

 tion. 



Alkaline Barium Chloride Solution. Two volumes of baryta- 

 water and one volume of barium chloride solution. 

 Almen's Solution. Dissolve 4 g. of tannin hi 8 cc. of 25 per 

 cent, acetic acid and then add 190 cc. of 40 to 50 per 

 cent, alcohol. 

 Ammonia. *A solution of ammonia in water, specific gravity 



0.96, containing about 10 per cent. NH 3 . 

 Ammonium Carbonate. One part 1 of the commercial ammo- 

 nium carbonate, one part of ammonia, and four parts of 

 water. Must stand some days before being used. 

 Ammonium Chloride, 1:10. 2 



Ammonium Molybdate in acid solution. Dissolve 50 g. of 

 molybdic acid in 200 g. of 8-10 per cent, ammonia and 

 pour the solution into 750 g. of nitric acid, specific 

 gravity 1.2. Let stand for some days in a warm place 

 and then decant. 

 Ammonium Oxalate, 1 : 25. 



1 By parts is always meant parts by weight. 



2 Distilled water is always to be used as the solvent; 1 : 10 means 1 part 

 by weight of ammonium chloride dissolved in 10 parts by weight of water. . 

 The water, of course, is to be measured. 



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