87 



Following upon these experiments with the soft resin of hop, it 

 was thought of interest to study the influence of the separate con- 

 stituents of soft resin (at least a- and /3-resin) on various sarcinae. 

 For this purpose the author 1 employed the crystallized a- and /3-hop 

 bitter acids. The experimental results show that : 



1. The a- and /2-hop resins retard the reproduction of various 

 sarcina organisms, the conditions as to stage of development being 

 identical. 



2. The a-resin is less effective than the /2-resin. 



3. The /3-resin may even exert a germicidal effect on certain 



species of sarcinae. 



4. The various species of sarcinae (and Pediococci) are 



dissimilarly influenced by the hop resins. 



The action of the individual constituents of the hop on various 

 lower organisms having been considered, it remains to make some 

 reference to their effect on higher organisms, and, more particularly, 

 on warm-blooded animals. The earliest communication of the kind 

 came from DRESER 2 , who employed in his experiments material sup- 

 plied by BUNGENER. Owing to the fact that the yS-hop-bitter acid 

 is readily precipitated from alkaline solutions by weak acids, even 

 carbonic acid being operative in this way, some difficulty was 

 experienced when introducing the acid into the organism. It 

 appears, however, that the acid, when administered internally, pro- 

 duced no abnormal effects on the animals experimented upon. 

 Direct injection into the circulation resulted in an increase of the 

 blood pressure, and restricted respiration. Resin isolated from beer, 

 as also resin obtained from the crystallised bitter acid, was found to 

 be quite indifferent. 



Subsequently, FARKAS S instituted similar experiments with the 

 a-acid, and found its action in many respects to resemble that of the 

 /J-acid, as reported by DRESER. The main difference was that the 

 a-acid attacks the central nervous system less and the peripheral 



1 Zeitschrift f. d. ges. Brauwtsen, 1901, 333. 



2 Archiv Jur experimentelle Pathologic & Pharmacologie, 1887, 129. 



3 Archiv fur die gesammte Physiologic, 1902, 92, 6r t 



