6 BULLETIN 568, U. S. DEPARTMENT OF AGRICULTURE. 



From two samples of sulphur several pieces of different appearance 

 were picked out, ground, and analyzed for arsenic, with the results 

 given in Table IV. 



Table IV. — Arsenic in different pieces of sulphitr from the same field sample. 



No. 



Sub- 

 sample. 



Appearance. 



Arsenic 

 as As 2 3 

 (parts per 

 million). 



No. 



Sub- 

 sample. 



Appearance. 



Arsenic 

 as As.0 3 

 (parts per 

 million). 



179 

 179 

 179 



1 

 2 

 3 



4 

 1 



Greenish, yellow 



Slightly orange, porous.. 

 More orange than sub- 



10 

 270 



160 

 66 • 

 35 

 80 



188 



188 

 188 



188 

 188 



3 



4 

 5 



6 



7 



Lemon yellow, largely 

 crystalline 



Orange, vitreous 



Lemon yellow, crystal- 

 line 



Orange, vitreous 



do 



160 

 150 



179 



1S8 



Average of the sample. . . 



50 

 450 



1S8 



2 



do 



300 













After a small part of sample 179 had been removed in subsamples 

 1,2, and 3, the remainder was ground and used as an average sample 

 of 179 in the same way in which the other samples of sulphur were 

 used. It is believed that the average value of 66 parts per million is 

 not appreciably different from that which would be obtained for the 

 arsenic in sample 179 if no subsamples had been removed. So many 

 subsamples of sample 188 were taken that it was not possible to obtain 

 an average value of this sample. 



The results of analyses of the subsamples of sample 179 indicate 

 that with sulphur taken from a lot containing on the average 66 

 parts of arsenic per million, one kiln of hops might be treated with 

 fumes from sulphur containing 270 parts of arsenic per million, while 

 the next treatment might be with sulphur containing only 10 parts 

 of arsenic per million. 



Since only a small quantity of sulphur is burned at one time in 

 curing hops, it is very probable that the sulphur used on a particular 

 kiln of hops will not contain the same quantity of arsenic as an 

 average sample of the sulphur on hand. 



The results -for the subsamples of sample 188 show irregularity of 

 distribution of arsenic much like that in sample 179. The relation 

 between the arsenic in sulphur and in the hops for which the sul- 

 phur is used can not be. very definite. No uniform quantity of sul- 

 phur is used for a given quantity of hops; the arsenic is not uni- 

 formly distributed through the hops in the kiln at one time and the 

 arsenic is not uniformly distributed through the sulphur. 



The analyses of samples 190, 220, and 227 show that siuphur can 

 be obtained which is practically free from arsenic. The analyses of 

 samples of hops cured with sulphur containing very little arsenic 

 indicate that hops may be cured with sulphur containing as much as 

 10 parts of arsenic per million without becoming contaminated with 

 more than 0.5 part of arsenic per million parts of hops. 



