90 



substance in question was stated by GRIESSMAYER not to be bitter. 

 It is indeed questionable whether any appreciable part of the hop 

 " bitter " is due to alkaloidal bodies, for the various bitter substances 

 which have been isolated by different investigators have almost invari- 

 ably been of an acid nature (cf. Brewing Trade Review, 1903, 17, 216- 

 219). PERSONNE indeed (Compt. Rend., 1854, 39) claimed to have 

 obtained an alkaloidal bitter from hops, but as he did not prepare 

 the substance in question in anything approximating to a pure state, 

 little weight can be attached to this assertion. GRIESSMAYER 

 obtained, in addition to " lupulin," considerable quantities of 

 trimethylamine in the course of the distillation of the aqueous hop- 

 extract with potash or magnesia. This is of interest, inasmuch as it 

 is in all probability a decomposition product of cholin, which was 

 obtained from hops by GRIESS and HARROW (Ber. 18, 7170). Cholin, 

 in its turn, is probably not present as such in hops, but results from 

 the splitting up of the more complicated base lecithin. As cholin 

 has been shown to be present in unhopped wort in considerable 

 quantities by KJELDAHL, this base (the term " alkaloid " is perhaps 

 scarcely appropriate here) cannot be considered to be specifically 

 introduced into beer by way of the hop. 



MICHEL (Versuchstats. Ber. 14) claims to have isolated a non- 

 volatile liquid alkaloid, which he also terms " lupulin." It is not 

 clear whether this substance is to be considered as identical with 

 GRIESSMAYER'S alkaloid of the same name. MICHEL states that 

 this alkaloid has been mistaken by analysts for coniine and 

 colchicine. In this connexion it is of interest to recall GRAHAM'S 

 (J. Chem. Soc., 5, 173) historical investigation, which resulted in 

 completely dispelling the somewhat (at that time) prevalent idea 

 that strychnine was used for the purpose of imparting additional 

 bitterness to bitter ales. WILLIAMSON (Chemiker Zeit., 1886, 20, 38, 

 147) extracted American hops with a solution of sugar, evaporated 

 in a partial vacuum at a low temperature, and subsequently 

 treated the extract so obtained with alcohol. The alcoholic extract 

 yielded a residue which possessed powerful narcotic properties. 

 This was further purified with dilute ammonia, ether, chloroform, 

 benzene, and by recrystallisation. In this way WILLIAMSON 

 obtained what he considered to be two new alkaloids, the one a 



