THE PRESENCE OF ARSENIC IN HOPS. 7 
CONCLUSIONS. 
The work here reported shows that sun-dried hops collected from 
various yards in Oregon in 1915 contained practically no arsenic. 
The spraying materials in general use, such as solutions of whale- 
oil soap and quassia or nicotin sulphate are not to be held respon- 
sible for the contamination of hops with arsenic. 
The sulphur in use in 1914 and 1915 was generally contaminated 
with arsenic, many samples containing over 100 parts of arsenic as 
As 2 3 in 1,000,000 parts of sulphur. When such sulphur is used in 
curing hops, the hops may contain three or four parts of arsenic per 
million parts of hops. 
Little, if any, doubt remains that impure sulphur alone is respon- 
sible for the contamination of hops with appreciable quantities of 
arsenic. 
ADDITIONAL COPIES 
OF THIS PUBLICATION MAT BE PROCURED FROM 
THE SUPERINTENDENT OF DOCUMENTS 
GOVERNMENT PRINTING OFFICE 
■WASHINGTON, D. C. 
AT 
5 CENTS PER COPY 
