Nov. 12, 1917 
Jonathan-Spot and Scald of Apples 
303 
in an Arnold sterilizer. The finely divided condition of the pulp may 
have made heating unnecessary for the extraction of the acid, but it was 
found that the hot extract could be filtered much more readily than the 
cold. The filtration was accomplished by means of ordinary filter paper. 
The pulp was allowed to drain and was then washed with distilled water 
until the total volume of the filtrate and washings equaled 12.5 c. c. for 
each gm. of original pulp. The filtrate was titrated against A/20 
sodium hydroxid, using the color changes of the extract as an indicator 
described by Schley (18) and by Culpepper, Foster, and Caldwell (8). 
In the titrations, as well as in all the other steps of the procedure, the 
corresponding samples from the open and from the closed containers 
were carried through the 
tests side by side. The 
results of the analyses are 
given in Table III. 
The method for sugar 
determination was essen¬ 
tially the same as that em¬ 
ployed by Bryan, Given, 
and Straughn (4), with 
the exception that the 
extraction was made with 
water instead of alcohol. 
Earlier tests on the effi- 
ciencyof thesampling press 
had shown that macera¬ 
tion was so thorough that 
the sugar of the pulp could be completely extracted with cold water in 
five minutes. The samples consisted of 20 gm. and, as already men¬ 
tioned, the pulp was free from core, seeds, and peel. The proteins were 
precipitated with neutral lead acetate and the excess of lead precipi¬ 
tated with sodium oxalate. Inversion was accomplished by adding 5 c. c. 
of concentrated hydrochloric acid to 50 c. c. of lead-free solution and 
allowing it to stand overnight. The hydrochloric acid was neutralized 
with anhydrous sodium carbonate. The total sugars were determined 
by the Allihn 1 method, the cuprous oxid being determined by direct 
weighing. The results of the analyses are given in Table III. 
In connection with the work on acids and sugars, dry-weight deter¬ 
minations of the pulp were also made, but only on the fruit that had 
been stored at 5 0 . In these tests the pulp was dried in an electric oven 
that stood at a constant temperature of ioo°. The corresponding 
samples from the open and closed containers were always moved together, 
and care was taken to secure the lowest dry weight of the pulp. The 
1 WlLEY, H. W., ed. OFFICIAL AND PROVISIONAL METHODS OF ANALYSIS, ASSOCIATION OF OFFICIAL 
AGRICULTURAL CHEMISTS. AS COMPILED BY THE COMMITTEE ON REVISION OF METHODS. U. S. Dept. 
Agr, Bur. Chem. Bui. 107 (rev.), 272 p., 13 fig. 1908. Reprinted in 1912. 
Fig. 20.—Graphs showing the development of color on Grimes 
apples in storage. The graphs on the left were obtained with the 
apples in baskets; those on the right with similar apples in 
moist chambers. The two series of graphs show the gradual 
development of color at the different temperatures, the figures 
near the lines indicating the number of weeks between the 
starting of the experiment and the time of taking notes. The 
apples were placed in storage on September 22,1916. See figure 
14 for the development of scald. 
