Griessmayer (1874) has shown that hops contain Trimethylamine, and in small proportion a liquid volatile alkaloid not yet analysed, which he terms Lupuline. The latter is stated to have the odour of conine, and to assume a violet hue when treated with chromate of potassium and sulphuric acid.
Lastly, Etti also found arabic (pectic) acid, phosphates, nitrates, malates, citrates, and also sulphates, chiefly of potassium, to occur in hops. The amount of ash afforded by hops dried at 100° C. would appear to be on an average about 6-7 per cent.
Production and Commerce—England was estimated as having in 1873, 63,276 acres under hops. The chief district for the cultivation is the county of Kent, where in that year 39,040 acres were devoted to this plant. Hops are grown to a much smaller extent in Sussex, and in still diminished quantity in Herefordshire, Hampshire, Worcestershire and Surrey. The other counties of England and the principality of Wales produce but a trifling amount, and Scotland none at all.
In continental Europe, hops are most largely produced in Bavaria and Württemberg, Belgium and France, but in each on a smaller scale than in England. France in 1872 is stated to have 9223 acres under hops.[2058]
Notwithstanding the extensive production of hops in England, there is a large importation from other countries. The importation in 1872 was 135,965 cwt., valued at £679,276: of this quantity, Belgium supplied 66,630 cwt., Germany 36,612 cwt., Holland 16,675 cwt., the United States 10,414 cwt., France 5,328 cwt. During the same period hops were exported from the United Kingdom to the extent of 31,215 cwt.[2059]
Uses—Hops are administered medicinally as a tonic and sedative, chiefly in the form of tincture, infusion or extract.
GLANDULÆ HUMULI.
Lupulina; Lupulin, Lupulinic Grains; F. Lupuline; G. Hopfendrüsen, Hopfenstaub.
Botanical Origin—Humulus Lupulus L. ([see preceding article]). The minute, shining, translucent glands of the strobile constitute when detached therefrom the substance called Lupulin.
History—The glands of hop were separated and chemically examined by L. A. Planche, a pharmacien of Paris, whose observations were first briefly described by Loiseleur-Deslongchamps in 1819.[2060] In the following year, Dr. A. W. Ives of New York[2061] published an account of his experiments upon hops and their glands, to which latter he applied the name of Lupulin. Payen and Chevallier, Planche and others, made further experiments on the same subject, endorsing the recommendation of Ives that lupulin (or, as they preferred to call it, Lupuline) might be advantageously used in medicine in place of hops.