GLA^.DUL^ HUMULl. 555 



provided with the stalk is built up of tabular pol3'hedric cells, whilst 

 the upper hemisphere shows a continuous delicate membrane. This 

 part therefore easily collapses, and thus exhibits a variety of form, the 

 greater also as the grains turn pole or equator to the observer.^ 



The hop gland is filled with a thick, dark brown or yellowish liquid, 

 which in the drug is contracted into one mass occupying the centre of 

 the gland. It may be expelled in minute drops when the wall is made 

 to burst by warming the grain in glycerin. The colouring matter, to 

 which the wall owes its fine yellow colour, adheres more obstinately to 

 the thinner hemisphere, and is more easily extracted from the thicker 

 part by means of ether. 



Chemical Composition — The odour of lupulinic grains resides in 

 the essential oil, described in the previous article. The bitter principle 

 formerly called Lupulin or LupuUte was first isolated by Lermer (18G3) 

 who called it the hitter acid of hops {Hopfenhittersdure). It crystallizes 

 in large brittle rhombic prisms, and possesses in a high degree the 

 peculiar bitter taste of beer, in which however it can be present only in 

 very small proportion, it being nearly insoluble in water, though easily 

 dissolved by many other liquids. The composition of this acid, 

 C*"H*'0^ appears to approximate it to absinthiin ; it is contained in the 

 glands in but small proportion. Still smaller is the amount of another 

 crystallizable constituent, regarded by Lermer as an alkaloid. 



The main contents of the hop gland consist of wax {Myncylic 

 jmhiiitate, according to Lermer), and resins, one of which is crystalline 

 and unites with bases. 



A good specimen of German lupulin, dried over sulphuric acid, 

 yielded us 73 per cent, of ash. The same drug exhausted by boiling 

 ether, afforded 768 per cent, of an extremely aromatic extract, which 

 on exposure to the steam bath for a week, lost 303 per cent., this 

 loss corresponding to the volatile oil and acids. The residual part was 

 soluble in glacial acetic acid and could therefore contain but very little 

 fatty matter. 



Uses — The drug has the properties of hops, but with less of 

 astringency. It is not often prescribed. 



Adulteration— Lupulin is apt to contain sand, and on incineration 

 often leaves a large amount of ash. Other extraneous matters which 

 are not unfrequent may be easily recognized by means of a lens. As 

 the essential oil in lupulin is soon resinified, the latter should be pre- 

 ferred fresh, and should be kept excluded from the air. 



^ For a full account of the formation of be found in Mehu's Etude du Houblon et du 

 the glands, see Trecul, Annalen des Sckncea Lupulin, Montpellier, 1867. 

 Xat. , Bot. , i. (1854) 299. An abstract may 



