Du Mez—The Galenical Oleoresins. 
1095 
with vague and contradictory statements. 10 Foi practical pur¬ 
poses, the classification of Hayduck * 11 appears to be the most 
useful. This investigator distinguishes three resins, which he 
designates a, (3 and y, according to their solubility in petroleum 
ether and their behavior toward a solution of lead acetate. The 
a - and j8- resins are soluble in petroleum ether, and are further 
known as the “soft resins,” being of a soft consistence at the 
ordinary temperature. The y-resin is insoluble in petroleum 
ether, but soluble in ether or alcohol. It is also known as the 
“hard resin.” 
The soft resins are supposed to contain the valuable bitter 
substances present in hops. From these resins, Lintner and 
Schnell 12 isolated two crystalline bitter substances of an acid 
nature. One of these, C 15 H 24 0 4 , they proposed naming 
“ humulon; ” 13 the other, they have designated “lupulic acid.” 14 
According to Chapman, the total resins constitute more than 
55 per cent, of the lupulin. 15 
Wax. According to Lermer 16 the wax is insoluble in 90 per 
cent alcohol and can be obtained by treating the ethereal extract 
with this solvent. He identified it as myricyl palmitate. As 
Power, Tutin and Rogerson 17 report the presence of ceryl alco¬ 
hol and cerotic acid in hops, it is quite probable that ceryl 
cerotate is also a constituent of the wax. 
Alkaloids. Choline 18 (C 5 H 15 0 2 N) is the only base occurring 
in lupulin, the identity of which has been established. There 
is, however, considerable evidence of the presence of a volatile 
10 The theory advanced by Seyffert (Zeitschr. ges. Brauw. (1896), 19, p. 1 
namely, that the hop resins are mixtures of substances in a progressive state 
of change is probably correct. Confirmation of this' theory is to be found 
in the work of Russell who states that a portion of the “soft resin’” is con¬ 
verted into the “hard resin” upon keeping the hops in storage. U. S. Dept. 
Agric., Bull. No. 282 (1915), p. 9. 
11 Wochenschr. f. Brau. (1887), 4, p. 397; Ibid. (1888), 5, p. 937. 
^Zeitschr. ges. Brauw. (1904), 27, p. 666. 
13 “Humulon” is very likely identical with the “hop-bitter acid” of H. Bun- 
gener, (Bull. Soc. Chim. (18SS6), 45, p. 487), and the “a-lupulic acid” of 
Barth. Zeitschr. ges. Brauw. (1900), 23, pp. 509, 537, 554, 572 and 594. 
14 “Lupulic acid” corresponds to the “j8-lupulic acid” of Barth, l. c. 
15 1. c. 
61 Dingier’s Folytech. Journ. (1863), 169, p. 54. 
17 l. c. 
18 Griess and Harrow have shown that hops contain not over 0.02 per cent, 
of choline. Ber. der deutsch. chem. Ges. (1885). 18, p. 717. 
