2 BULLETIN 99», TJ. S. DEPARTMENT OF AGRICULTURE. 
At various times attempts have been made to utilize the culls 
from the lemon industry. The first effort which was ultimately 
successful was that of a company, organized in 1898, now manu- 
facturing essential oils and citrate of lime. Another company, estab- 
lished early in 1914, at present produces citric acid and essential oil. 
Several smaller firms are making citric acid, citrate of lime, and 
bottled lemon juice. As the history of the undertaking has been 
treated by others (3) (4), it need not be considered further here. 
PURPOSE OF INVESTIGATION. 
So far as known, there has been no systematic attempt to study 
the composition of the California lemon. Analyses of scattered 
samples have been published, but no series of results from carefully 
selected trees, where sampling was continued throughout the season, 
has been reported. It is highly desirable that this information be 
made accessible to the lemon grower, as well as to the lemon by- 
product manufacturer, who is especially interested in the oil and 
acid content of the fruit which he purchases. 
INVESTIGATIONAL WORK. 
METHOD OF SAMPLING. 
In a territory as extensive as the lemon-growing section of Califor- 
nia, adequate sampling presents many difficulties. Since the number 
of samples which can be examined is necessarily limited by the size 
of the laboratory force and its facilities, care was taken to select 
typical locations in each well-recognized growing district. In some 
instances, circumstances prevented sampling, so that a small number 
of centers are not adequately represented, and in a few cases certain 
districts are more fully represented than was at first planned. In 
all, satisfactory samples were taken in about 20 locations in the 
following centers: Bonita, Chula Vista, Escondido, Whittier, Santa 
Paula, Carpenteria, San Fernando, Glendora, San Dimas, and Clare- 
mont. From other work conducted at the same time it was possible 
to obtain data on fruit grown at Corona. 
The trees selected originally were such as to give an equal number 
of locations of the Eureka and Lisbon varieties. Because of irregular 
sampling, the final selections consist of 10 Eureka and 6 Lisbon 
trees. The judgment of experienced growers was the deciding factor 
in selecting typical trees. It is possible that some of the trees in- 
cluded in the final results are not of the best strains, but, as many 
groves of such trees exist in the State, the effectiveness of the data is 
not materially impaired. 
Again, the number of fruits to each sample was a matter of con- 
cern. Manifestly, the larger the number the better the chance of 
satisfactorily representing the composition of the grove or district 
