36 
Journal of Agricultural Research 
Vol. VII, No. i 
acid synthetic media, and also that the acidity of juice from infected 
apples was materially decreased. Further studies of this point by Reed 
and Grissom (20) brought out the fact that this production of alkalinity 
in culture media is due, at least in part, to the production of carbon dioxid 
and the resulting formation of carbonates, in part to the formation of 
ammonia from the peptone of the media, and in part to the formation of 
ammonia and purin and hexone bases as a consequence of the autolysis 
of the proteins of the fungus (19). That none of these causes is active 
in the reduction of acidity produced by Sphaeropsis malorum is evident 
from the fact that the nitrogen of the alcohol-ether-water-soluble frac¬ 
tion, as well as the ammonia therein present, steadily decreases as the 
disease proceeds, a fact quite precluding the possibility of the formation 
of hexone or purine bases. The results point rather conclusively to the 
destruction of organic acids by oxidation as a cause of the observed facts. 
That this is the true explanation is borne out by the fact that Wolf, in the 
course of studies conducted in this laboratory (28), has observed that a 
species of Phoma is capable of decreasing the acidity of several species 
of Citrus without a concurrent increase in the soluble nitrogenous con¬ 
stituents. Cooley (3) and Hawkins (4), in their studies of the chemical 
changes produced in the peach by Sclerotinia cinerea , found that the devel¬ 
opment of the fungus was accompanied by a marked rise in the acidity of 
the tissues, and Cooley showed that this was due to the production of 
oxalic acid, which was absent from the plum and peach juices used as 
culture media. That we are here dealing with activities of an entirely 
different character is evident; there is absence of acid formation with 
progressive decomposition of the acids naturally present in the fruit. 
ALCOHOL DETERMINATIONS IN SOUND AND DISEASED APPLES 
Samples for alcohol determination were prepared from sound, half- 
decayed, and wholly decayed fruits by grinding, weighing 200-gm. sam¬ 
ples into distillation flasks, and adding 500 c. c. of distilled water to each 
sample. The flasks were then attached to condensers and distillation 
continued until alcohol had ceased to come over and a total of 100 c. c. 
of distillate had been obtained from each flask. Determinations of 
alcohol in these distillates were made according to the method originally 
devised by Nicloux (14), as described by Pringsheim (17), which is based 
upon the oxidation of the alcohol by potassium bichromate. Five c. c. 
of each distillate was placed in a beaker, a small measured quantity of 
N/20 potassium bichromate added, 35 c. c. of concentrated sulphuric 
acid poured in, and the solution heated. The solution was then con¬ 
tinuously stirred while N/20 potassium bichromate was cautiously added 
from a burette until the completion of the oxidation was indicated by 
a change in the color of the solution from greenish blue to yellowish 
green. The comparative results are as follows: For normal apples, 5 c. c. 
distillate required 19.4 c. c. of potassium bichromate; for half-decayed 
fruits, 5 c. c. required 22.3 c. c. of potassium bichromate; for completely 
decayed fruits, 5 c. c. required 30.6 c. c. of potassium bichromate. 
