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 MAY BE PROCURED FROM 



THE SUPERINTENDENT OF DOCUMENTS 



GOVERNMENT PRINTING OFFICE 



"WASHINGTON, D. C- 



AT 



5 CENTS PER COPY 



