20, 1 Wells and Perkins: Nipa-sugar Manufacture 49 
as a good method for the chemical study of tuba. Since the 
completion of these experiments, however, toluene has become 
much cheaper, and its use may perhaps be considered as a com- 
mercial possibility. An advantange of its use is that it preserves 
the palm flavor and prevents darkening of the sap. 
An experiment on the preserving power of toluene was made 
in a cultivated Pampanga nipa swamp. Three groups of palms, 
the fruits of which had been cut at different times, were chosen, 
and bottles containing 7 cubic centimeters each of toluene were 
placed on ten palms of each group. The polarization of the 
tuba was tested after collection for one-half hour. In the A 
group this was done immediately in the swamp, but this was 
found to be unnecessary, and the others were analysed a few 
hours after collection. Group A, which had been producing 
tuba for about seventy-five days before the experiment, showed 
by direct polarization 10.6, 10.7, 10.8, 11.7, 11.8, 11.8, 12.3, 12.3, 
13.1, and 13.3 per cent sucrose. Group C, cut about forty days 
before the experiment, showed 13.6, 13.6, 13.8, 14.3, 14.6, 14.7, 
15.3, 15.4, 15.6, and 16.1 per cent sucrose. Group D, cut eleven 
days before the experiment, showed 18.2, 13.2, 13.4, 13.9, 14.6, 
14.8, 14.9, 15.4, 15.7, and 16.1 per cent sucrose. 
The behavior of composite samples from these groups on 
preservation under a layer of toluene is shown in Table 1. It 
may be seen that inversion took place slowly. Meanwhile the 
Brix of the five samples, 14.8, 14.3, 17.2, 17.2, and 17.3, remained 
constant within the limits of error, and a very slight acidity 
to phenolpthalein appeared, in no case exceeding 0.02 per cent 
(as acetic). 
TABLE 1.—Percentage of sucrose in tuba preserved under toluene. 
Two Six 
Group. Fresh, weeks. | weeks. Remarks. 
Per cent. | Fer cent. | Per cent. 
A as sea ary Sw ae 11.9 9.1 5.9 | Filtered. 
ES eee 12.0 10.0 6.7 | Not filtered. 
Ss on 14.9 14.2 12,5 | Filled to the cork with toluene. 
Ss 14.9 14.1 12.7 | Thin layer of toluene. 
_ | eC 14.6 13.0 10.1 
The quality of the tuba seems rather poor for Pampanga, 
probably because the work was done in March, which is not the 
natural tuba season in that province. These palms had been 
tapped late in order to lengthen the season. 
183677——4 
