ECONOMIC VALUE OF FUMIGATION 223 
infectant for nursery stock. The writer being aware 
of the use of this gas in California upon nursery stock 
as early as 1890, wrote Alexander Craw, State Ento- 
mologist and Quarantine Officer of California, who re- 
plies as follows: 
First use upon nursery stock.—‘‘ Fumigation by 
FIG. 83—SPRAYED ORANGE TREE 
Orchard of W. F. Stearns, near National City, California 
(Photograph by H. R. Fitch, July 18, 1901) 
hydrocyanic acid gas was practiced in Southern 
California for the disinfection of nursery stock as 
early as 1889-90. Upon page 479 of the ‘ Report of 
the California State Board of Horticulture for 1890’ 
the following reference to fumigating nursery trees is 
made: ‘The Commission has used the utmost vigi- 
