filter paper, and transfer the precipitate to a beaker by means of a 

 stream of hot water from the wash bottle, remove the part remaining 

 on the filter by allowing about 20 cc of warm dilute sulphuric acid to 

 pass over, then again wash with hot water. To the solution in the 

 beaker add 20 cc of concentrated sulphuric acid, then titrate with tenth 

 normal potassium manganate solution. 



SULPHUR (SO 3 ). 



In the remaining 50 cc of the solution of ash determine sulphates, 

 following the method given in Bulletin 46, page 75. 



POTASH (K2O). 



In the filtrate from the sulphate determination proceed as in the 

 Lindo-Gladding method. 



Express all results on manganese, calcium, sulphates, and potassium, 

 as per cent in ash of sample. 



(4) MALIC ACID. 



This determination affords interesting data, and is of great value in 

 doubtful cases. The author's results 1 on the pure sirups range from 

 0.84 to 1.28 (excluding 1.76 obtained on sample No. 4 Penn.), and on 

 the pure sugars from 0.98 to 1.67. When the results fall below these 

 minimum values there is evidence of adulteration with cane or so-called 

 brown sugar. It is safe to say that in the majority of cases the malic 

 acid value furnishes absolute evidence as to whether a sample contains 

 brown sugar. The malic acid values for the brown sugars, tabulated 

 by the author, 1 vary from 0.08 to 0.18. 



This determination is made by a modification of the calcium chlorid 

 method of Leach and Lythgoe. 2 Six and seven-tenths grams of the 

 sample are weighed into a 200 cc beaker, and water added to make a 

 volume of 20 cc. The solution is made slightly alkaline with ammonia, 

 1 cc of a 10 per cent solution of calcium chlorid added, then 60 cc of 95 

 per cent alcohol. The beaker is covered with a watch-glass and heated 

 for one-half hour on a water-bath, when the flame is turned off and the 

 beaker allowed to stand overnight. The material in the beaker is then 

 filtered through good quality filter-paper, the precipitate washed with 

 hot 75 per cent alcohol to freedom from soluble calcium salt, dried and 

 ignited. From 15 to 20 cc of tenth-normal hydrochloric acid is added to 

 the ignited residue, the lime thoroughly dissolved by careful boiling, and 

 the excess of acid titrated with a tenth-normal sodium hydroxid, using 

 methyl orange as an indicator. One-tenth of the number of cubic centi- 

 meters of acid neutralized expresses the result, which, for the present, 

 will be called the "malic acid value." 



1 Ibid. 



2 Jbid., No. 4, p. 380. 



