44 MISCELLANEOUS PAPERS. 



grown on soils containing arsenic may accumulate large amounts 

 of this element, most of which, as has been further shown by pot ex- 

 periments," occurs in the barley grains. Likewise. Gosio 6 records the 

 accumulation of arsenic in the leaves, stems, and fruits of squash 

 plants which had been watered with dilute arsenic solutions. 



In order to test the capability of the hop plant to take up arsenic 

 from the soil, two adjoining plats of sixty hills each were selected 

 in a hop yard and from May 24 to August 5. 1907. the alternate hills 

 of one plat were watered weekly with solutions of arsenious acid 

 and those of the other with solutions of arsenic acid. Each solution 

 was made up in five different strengths, the arsenious acid ranging 

 from 0.01 to 1 per cent and the arsenic acid from 1 to 3 per cent. 

 Solutions of each acid were then applied to fifteen groups of two 

 hills each in amounts so regulated as to form a gradually increasing 

 series. In this way the total amount of arsenious acid administered 

 ro the plants of each hill ranged from one-tenth of an ounce to 21 

 ounces and the arsenic acid from 2 to 20 ounces to each hill. When 

 the hops Avere mature, those from each group of two hills which had 

 received the same treatment were gathered separately, dried without 

 sulphur, and prepared for chemical examination. 



Upon analysis traces of arsenic, from 0.5 to 3 parts per million, 

 were found in each sample examined. While the amount of arsenic 

 in various samples was not in direct proportion to the amount admin- 

 istered to the plant, the balance of evidence is in that direction. 

 Necessarily the experimental error is very large, but when due allow- 

 ance is made for it the results warrant the conclusion that hops will 

 take up from soils containing available arsenic amounts relatively 

 proportional to the quantity contained therein. 



IMPURE SULPHUR AS A SOURCE OF ARSENIC. 



That the sulphur used in sulphuring hops frequently contains 

 small quantities of arsenic is quite generally known and has been 

 suo-o^ested as the source of the arsenic occasionally found in dried 

 hops." However, analysis of the different grades of sulphur in com- 

 mon use indicates that from the quantities applied in most cases suf- 

 ficient arsenic would not be produced to account for the traces some- 

 times found in hops, provided it was uniformly distributed through 

 them. Analysis shows that there is often wide variation in the 

 amount of arsenic contained in samples drawn from different bales 



« County Councils Cumberland, etc. Tech. Education Rept., vol. 10, pp. 1-121, 

 125-150, 1901. 



& Gosio, B. Atti r. Accad. Lincei. vol. 15, pp. 730-731, 1906 : abstract in Centbl. 

 Bak. Par. u. Infek., part 2. vol. IS, pp. 721-725. 1907. 



c Buffer. E. TVochenschr. f. Brauerei, vol. IS, p. 109, 1901. 

 121— iv 



