COMPOSITION OF CALIFORNIA LEMONS. 3 
from which the sample came. After removing the sample for the 
experimental work, the trees from which they were taken were picked 
in the usual commercial way. In a few cases an insufficient number 
of fruits had reached the proper size when time for the next sampling 
arrived. 
Both the Eureka and Lisbon varieties of lemons in California 
blossom throughout the year, and pickings of fruit are made monthly, 
except in September or October, when they are usually omitted. 
Whenever possible samples were taken at monthly intervals in the 
course of the investigation here reported. 
As a rule, from 18 to 24 fruits were forwarded to the laboratory in 
cardboard cartons furnished for the purpose. Seldom were they more 
than 24 hours en route. At the laboratory they were kept in the 
cartons in cool storage (40° to 50° F.) until analysis was begun. 
Usually not more than three days elapsed between the time of pick- 
ing and analysis. 
METHODS OF ANALYSIS. 
Unfortunately, in order to make a satisfactory determination of 
the essential oil of the fruit, it was necessary to divide the sample. 
After the specific gravity of the fruit had been determined by weigh- 
ing in the air and under water, this division was made as evenly as 
possible, both as to size and color. Half the sample was ground by 
being passed through a food grinder three times, and the oil was 
determined in a portion of it by steam distillation, according to the 
method of Wilson and Young (5) . The acidity of the whole fruit was 
determined on another portion of this sample by titration with 
alkali solution, using phenolphthalein as indicator. 
The remaining lemons were quartered, the thickness of the skin 
estimated, and the juice expressed by a small hand press. 
In estimating the thickness of the peel, the following arbitrary 
method was used: The cross section of the peel was measured in 
several places by calipers, and the average taken. When this was 
found to be less than 3 mm., the peel was designated as thin; 3 to 5 
mm., medium; and above 5 mm., thick (fig. 1). Rarely did peel 
exceed 7 mm. in thickness. 
The acidity of the juice was determined by titration against alkali. 
All acid is calculated as citric with the water of crystallization in- 
cluded. 
RESULTS OF INVESTIGATION. 
The data derived from the analyses of Eureka and Lisbon lemons 
grown in California are shown in Tables 1 and 2. Table 3 gives the 
results on samples of the Villa Franca variety; Table 4, those on 
samples of fruit from a Eureka location in central California; and 
Table 5, those on samples of lemons of an unknown variety from 
Arizona. It is not thought advisable to attempt to compare the 
results in Tables 3, 4, and 5 with those in Tables 1 and 2, for the 
reason that the number of Villa Franca locations was small, al- 
