226 



Journal of Agricultural Research voi. xxn.No.4 



from water it formed brown aggregates of large crystals containing one 

 molecule of water. (Calculated for CyHgOs. HjO, HjO, 9.57 per cent; 

 found, 9.39 per cent.) It was identified by the usual tests. Mr. N. A. 

 Lange made combustions of some of the purified acid and of its triacetyl 

 derivative, the results of which he kindly permits us to publish as follows : 



I. The acid gave C, 50.19 per cent; H, 3.92 per cent. Calculated for gallic 



acid: C, 49.40 per cent, H, 3.56 per cent. 



II. The acetyl derivative gave C, 53.91 per cent; H, 4.13 per cent. Calculated 



for triacetyl gallic acid, C, 54.39 per cent; H, 4.06 per cent. 



The melting point of the triacetyl gallic acid, stated variously in the 

 literature from 151° to 165° and 166° C, was 162° to 163° C. 



After the removal of tannin and gallic acid the aqueous extract from 

 the berries was largely neutralized with calcium carbonate and filtered 

 hot, after considerable concentration. Alcohol threw out a voluminous 

 precipitate, the first fractions taffy-like, later ones solid. These fractions 

 were treated with enough hydrochloric acid to form the acid calcium 

 salt, and were repeatedly treated with animal charcoal and recrystallized 

 from hot water. 



The pure crystals were dissolved in water, exactly neutralized with 

 standard alkali; and normal silver malate was precipitated by the addi- 

 tion of silver nitrate. The four successive fractions of the crude calcium 

 salt were designated A, B, C, and D, and each was purified and converted 

 into the silver salt. In addition, a portion of fraction A was purified 

 by further recrystallization and was obtained in two portions called Aa 

 and Ab, from which silver salts were also prepared. The duplicate 

 analytical figures for all of the silver precipitates are given in Table I. 



Table I. — Duplicate analyses of silver salts prepared from a series of precipitates obtained 

 by fractional separation with alcohol from an aqueous solution of calcium salts of the 

 organic acid of the sumac fruit 



Fraction. 



A-I... 



A-II. 



Aa-I. 



Aa-II 



Ab-I. 



Ab-II 



B-I... 



B-II. 



C-I... 



C-II. . 



C-III . 



D-I. . 



D-II. 



Weight of 

 silver salt. 



3.2895 

 •2133 

 •4385 



^•1358 

 .6137 

 .9674 

 ■4541 

 •6359 

 .4242 



•5015 

 .3921 



•4195 

 •5263 



Weight of 

 silver. 



0.1794 

 .1318 

 .2721 

 .7048 



•3794 

 .5962 

 .2806 



•3932 

 .2624 



•3099 

 .2420 

 .2596 

 •3259 



Percentage 

 of silver. 



61.96 

 61.79 

 62.05 

 62.05 

 61.82 

 61.63 

 61.79 

 61.83 

 61.85 

 61.79 

 61.71 

 61.88 

 61.92 



