18 BULLETIN 993, tT. S. DEPARTMENT OF AGRICULTURE. 
two sets of locations, and a more pronounced difference in the acid 
content. If, however, the location at Carpenteria, which is apparently 
abnormal as to the oil and acid content of the fruit, is discarded, 
the averages are too nearly the same to render any conclusion possible. 
These data are offered not as a final statement upon the subject of 
the difference in composition between coastal and inland lemons, 
but merely to show that so far no difference has been found. 
CONCLUSIONS. 
A few well-defined differences between the varieties of lemons 
examined exist, the most striking of which is in the specific gravity 
of the fruit. The specific gravity of the Eureka variety is greater 
than that of the other varieties, and that of the Villa Franca appears 
to be practically the same as that of the Lisbon variety. 
The Villa Francas have more oil than the Eurekas. Otherwise no 
absolute difference in the oil content is shown, although there is some 
indication that the Eureka has the lowest oil content. 
There is no difference in the acid content of the three varieties. 
A marked difference in sugar content between Eureka and Lisbon 
lemons exists. 
The acidity of lemons is highest in the early fall. Lemons have 
the lowest specific gravity during the winter months and the highest 
in midsummer. Their oil content is lowest in late winter and spring 
and highest in the fall. 
No absolute correlation between the color of the peel and the com- 
position of the fruit was found. As the thickness of the peel increases, 
the specific gravity of the fruit decreases, as does the acid content. 
No correlation is shown between color and thickness of the peel. 
No difference in composition between lemons grown on the coast 
and those grown inland is shown. 
BIBLIOGRAPHY. 
(1) Shamel, A. D., Scott, L. B., Pomeroy, C. S., and Dyer, C. L. 
1920. Citrus-fruit improvement: A study of bud variation in the Eureka 
lemon. TJ. S. Dept. Agr. Bull. 813: 1-88. 
(2) • 
1920. Citrus-fruit improvement: A study of bud variation in the Lisbon lemon. 
TJ. S. Dept. Agr. Bull. 815: 1-70. 
(3) Will, R. T. 
1916. Some phases of the citrus by-product industry in California. J. Ind. 
Eng. Chem., 8: 78-86. 
(4) Wilson, C. P. 
1921. The manufacture of citric acid from lemons. Calif., Citrograph, 6: 110. 
(5) — and Young, C. O. 
1917. A method for the determination of the volatile oil content of citrus fruits. 
J. Ind. Eng. Chem., 9: 959-961. 
