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- 



