1088 Wisconsin Academy of Sciences, Arts, and Letters. 
omitted from the present revised edition. It has never re¬ 
ceived recognition by any of the foreign pharmacopoeias. 
Drug Used, Its Collection, Preservation, Etc. 
Lupulin has not been included in the late edition of the United 
States Pharmacopoeia. In the preceding edition, it was defined 
as “the glandular trichomes separated from the fruit of Humw- 
lus Lupulus Linne (Fam. Moraceae).” 
The drug, as it occurs on the market, is of varying degrees of 
purity due, principally, to the method of obtaining it While 
some of it is probably obtained by picking the scales from 
the fruits and then shaking or rubbing the glands through a 
fine sieve, the bulk of the. commercial article consists of the 
sweepings gathered up from the floors of the hop bins. 1 Such 
being the case, it is only natural to expect contamination with 
sand and other earthy materials. The impurities, in part, are 
usually removed by washing with water when the sand settles 
to the bottom and the lupulin is skimmed off and dried. 
The glands, on storing, especially if exposed to the air, 
undergo a change, becoming dark brown in color and developing 
a rancid odor. Rabak 2 and Russell, 3 respectively, have shown 
one of the changes to be a conversion of the so-called soft resin 
into the hard. The development of the disagreeable odor has 
been attributed to the formation of valeric acid 4 resulting from 
the oxidation of one or more of the constituents. In view of the 
foregoing, the British Pharmacopoeia directs that the drug be 
renewed annually and rejected as soon as it becomes dark in 
color or developes a cheesy odor. 
In this connection, it should also be stated that hops are often 
sulphured previous to storing. To what extent, if any, this 
treatment affects the quality of the lupulin obtained therefrom 
and later the oleoresin, does not appear to have been determined. 
1 Flueckiger, Pharmakognoise des Pflcmzenreichs (1891), p. 255. 
2 Bull. No. 271, U. S. Dept, of Agric. (1913), p. 13. 
3 Bull. No. 282, U. S. Dept of Agric. (1915), p. 9. 
4 Bungener, Pharm. Journ. (1884), 43, p. 1008. 
