212 On the Chemical and Natural History of Lupuline. 



To obtain this resin as pure as possible, tlie lupuline must 

 be exhausted by long boiling in water, which drives off the 

 volatile products, and dissolves the bitter matter. The in- 

 soluble residue, composed of resin and of disintegrated tissue 

 of the lupuline grains, well v/ashed and dried, is then treated 

 by boiling alcohol, which sets free, when cooled, a certain 

 quantity of ivaxy matter ; the alcoholic liquor, filtered after 

 cooling, furnishes the resin by evaporation of the alcohol. 



The wax is contained in the cells which compose the 

 cupule of the lupuline grain ; it exists also in the scales 

 which constitute the cone of the hop, and by treating these 

 scales with boiling alcohol, it is procured in sufficient quan- 

 tity. It is dry and pulverulent, inodorous and tasteless ; it 

 begins to soften at +80 degrees (176° Fahr.), and is fully 

 melted at +100 degrees (212° Fahr.) Strongly heated, it 

 gives two volatile products, which diffuse an odour of wax ; 

 it burns without residue, producing a white shining flame ; 

 this matter resembles, as we see by its properties, the wax 

 of the sugar cane. 



Explanation of Plate II, 



Fig. 1. Cone of Hop. 



Fig. 2. Terminal bud enveloped by the stipules, s s, on which are marked 

 the granulations, which represent the cupules and the discs indi- 

 cated by the figures 14, 15, 16, &c. 



Fig. 3. Lupuline originating ; e e, epidermis ; I, primordial cellule of lupu- 

 line, by which it is attached to the epidermis ; a, cellule produced 

 by the preceding, and which gives rise to the following modifica- 

 tions : — 



Fig. 4. e, epidermis ; I, primordial cellule ; a, cellule divided transversely 

 into two ; the inferior division constitutes the pedicel of the lupu- 

 line, the superior forms the gland of the same. 



Fig. 5. e e, epidermis ; I, primordial cellule ; p, pedicel ; a, cellule contain- 

 ing grey matter with granules. 



Fig. 6. p, pedicel : a, cellule divided into two longitudinally. 



Fig. 7. p, pedicel ; a, represents one of the] two cells of the preceding figure, 

 subdivided longitudinally into two ; a', is another cellule, not so 

 parted. 



Fig. 8. e, epidermis ; p, pedicel ; a, gland formed of four cellules. 



Fig. 9. Gland, represented in figure 7, front view ; a, is the cell not divided ; 



a', the cell which is parted into two longitudinally. 

 Fig. 10. Gland a of the figure 8, front view. 



Fig. 11. The same gland more advanced, in which are seen many cells origi- 

 nating by the intra-utricular mode of multiplication. 



