6 BULLETIN 773. U. S. DEPARTMENT OF AGRICULTURE. 
50 cubic centimeters, and the method for total tartaric acid in wines 1 
applied. Xo tartaric acid "was detected. 
Formic acid was tested for in several samples by Fincke's method. 2 
Three samples tested gave from 3 to 4 milligrams of formic acid per 
100 cnbic centimeters. . 
Benzoic and salicylic acids, for which tests were made in the ether 
extract of the juices, were found to be absent. 
RESULTS OF ANALYSES. 
Table 1 gives the analyses of the pure Logan blackberry juices in 
terms of percentage by weight, and Table 2 gives them as grains per 
100 cubic centimeters. The juices are classified into those of the 
season of 1916. which were obtained from Oregon and Washington, 
and those of the season of 1917, obtained from California only. The 
Washington and California juices were expressed from the fresh fruit 
in the laboratory, while the Oregon juices were obtained directly 
from the factories. Table 3 shows the results of the analyses of 
commercial beverages and sirup as they appear on the market, and 
Table 4 shows the approximate composition of these products as 
determined from Table 3. For convenience of comparison the 
analyses of the commercial beverages and sirup, as well as of the 
expressed juices, are given in terms of percentage. Because of the 
addition of sugar to the commercial products, a comparison on the 
basis of grams per 100 cubic centimeters would be difficult. The 
data on the pure juices most valuable for the interpretation of analyses 
have, therefore, been restated in terms of percentage by weight. 
i U. S. Dept. Agr., Bur. Chem. Bui. 107, rev., 86. 2 j 0U r. A. 0. A. C (1916) f, 1: 94. 
