282 § 142. BEVERAGES. 



the wine, let the mixture stand several days in a well- 

 closed bottle, and then titrate 30 c.c. of the clear liquid 

 with the standard sodic solution ; subtract 0.3 c.c. from, 

 the amount of soda required, and then subtract this re- 

 mainder from the amount that would be required, as in 

 Jc^ to neutralize the total free acid in 10 c.c. of wine ; this 

 second remainder represents the quantity of acid that was 

 removed from the wine by treatment with alcohol ; for 

 each cubic centimetre of this remainder calculate 0.1881 

 grm. of tartar. 



Griffin estimated tartar by evaporatmg 100-200 c.c. of 

 the wine to dryness, incinerating the residue, determining 

 potassic carbonate in the ash with the aid of the standard 

 acid, and allowing one equivalent of tartar for every 

 equivalent of potassic carbonate thus found in the ash. 



He estimated it also by adding 25 c.c. of alcohol and 

 as much ether to 10 c.c. of wine, letting the mixture 

 stand 24 hours, collecting the precipitate on a dried and 

 weighed filter, drying it at 100° C, and weighing it ; 

 all but about 0.002 grm. of the tartar will be precipitated 

 in this way. 



m. Total tartaric acid. — Evaporate 100 c.c. of the wine 

 to about half its volume, jorecipitate the acid by lime- 

 water in slight excess, filter the precipitate out, boil it 

 with a solution of potassic carbonate, filter the liquid, 

 evaporate the filtrate somewhat, acidify it with acetic acid, 

 precipitate the potassic tartrate with considerable alcohol, 

 and collect and treat the precipitate as directed in § 71. 



n. Malic acid. — This is contained in the filtrate from 

 the calcic tartrate in m. To determine it, evaporate this 

 filtrate down to one-third, and jirecipitate the calcic malato 

 with alcohol, as directed in § 73. As this precipitate will 

 contain also the sulphuric acid, if any is present in the 

 wine examined, a determination of this acid should be 

 made in a portion of the wine, in the usual manner ; then 

 estimate the amount of calcic sulphate, CaSO^, ^H^O, in 



