STRTJCTUEE OF THE HOP CONE. 



287 



In the seed of the hop Gresshoff discovered 24-4 per cent, 

 of a bitter, ill-flavoured oil. 



Dr. Brand found decisive indications of boric acid in 

 the ash of hop cones ; and this acid is also present in the 

 leaves and stem of the plant. The other ash constituents 

 have already been dealt w^ith. 



Th^ follovnng analyses give an idea of the chemical 

 composition of the hop : — 



According to Behrens, 100 parts 

 hops, free of silica, contain : — 



of the dry matter of 



1 Erster Bericht ilber die Arbeiten der k. k. Versuchsstatiori in Wien aus 

 4en Jahren 1870-1877, Vienna, 1878. 



