74 
LON A. HAWKINS 
AUihn's tables. The method used for sugars was similar to that given 
by Bryan, Given and Straughn (lo). 
The total sugars were determined in the solution used for reducing 
sugars by inverting the sucrose in 50 cc. with hydrochloric acid, making 
the solution up to 100 c.c. and neutralizing with anhydrous sodium 
carbonate. The sugar was determined as in the case of the reducing 
sugar. The sucrose content was calculated from the difference in 
total and invert sugar in the sample, as is the usual procedure in 
investigations of this kind. Kulisch (7), Girard (5), Bigelow and Gore 
(2) and others have considered this difference between the total and 
reducing sugars in peaches to be due to sucrose. It was, however, 
considered worth while, in view of the work of Davis and Daish (4), 
to obtain more evidence upon this point. Accordingly, a number of 
peaches were sliced up, a little calcium carbonate added, and the 
mixture extracted with 70 per cent alcohol, for one week. The 
solution was then filtered and three samples of the filtrate measured 
out. These solutions were prepared for analysis in the same way as 
the solutions from samples of peaches in the inoculation experiments 
and the reducing sugars determined. For total sugars duplicate 
samples were pipetted from each of the three solutions. The one set 
of these was treated with acid in the usual way, while the sugar in the 
other set was inverted with invertase.^ The percentage of reducing 
sugar in the solutions and the percentage of total sugar as; found by 
both methods are given below: 
Per Cent Sugar as Glucose after Inversion (Total Sugar) 
Per Cent Reducing Sugar Acid Inversion Invertase Inversion ' 
0.77 3-34 3-37 
0.77 3-36 348 
0.77 347 346 
From these results it would seem probable that the increase in 
reducing substance after treatment with acids is due to the inversion 
of the cane-sugar in the solution. At any rate, according to the work 
of Hudson (6), the increase in reducing power is not due to the hydro- 
lysis of starch, dextrins or pentosans or to the inversion of maltose or 
lactose. The alcoholic sugar solution, from which the original samples 
were taken, was later cleared with lead acetate, filtered, and the excess 
lead removed as sulphide. The filtrate was evaporated and a sugar 
^ The writer's thanks are due Dr. C. S. Hudson, of the Bureau of Chemistry, 
for the invertase solution used in these experiments. 
