Page:EB1911 - Volume 13.djvu/695

Rh In hop gardens a few male plants, usually three or four to an acre, are sometimes planted, that number being deemed sufficient to fertilize the female flowers. The blossoms are produced in August, and the strobiles are fit for gathering from the beginning of September to the middle of October, according to the weather.

The cultivation of hops for use in the manufacture of beer dates from an early period. In the 8th and 9th centuries hop gardens, called “humularia” or “humuleta,” existed in France and Germany. Until the 16th century, however, hops appear to have been grown in a very fitful manner, and to a limited extent, generally only for private consumption; but after the beginning of the 17th century the cultivation increased rapidly. The plant was introduced into England from Flanders in 1525; and in America its cultivation was encouraged by legislative enactments in 1657. Formerly several plants were used as well as hops to season ale, hence the name “alehoof” for Nepeta Glechoma, and “alecost” for Balsamita vulgaris. The sweet gale, Myrica Gale, and the sage, Salvia officinalis, were also similarly employed. Various hop substitutes, in the form of powder, have been offered in commerce of late years, most of which appear to have quassia as a chief ingredient. The young tender tops of the hop are in Belgium cut off in spring and eaten like asparagus, and are forced from December to February.

Medical Use.—The principal constituents of the strobiles are lupulin, one of the few liquid alkaloids; lupulinic acid, a bitter crystalline body, soluble in ether, which is without any other pharmacological action than that common to bitter substances; Valerol, a volatile oil which in old hops undergoes a change to the malodorous body valerianic acid; resin; trimethylamine; a peculiar modification of tannin known as humulotannic acid; and a sesqui-terpene. The British pharmacopoeia contains two preparations of the strobiles,—an infusion (dose, 1-2 oz.) and a tincture (dose, -1 drachm). The glands obtained from the strobiles are known in pharmacy as lupulin, a name which tends to confusion with that of the alkaloid. They occur in commerce as a bright yellow-brown powder, seen under a lens to consist of minute glandular particles. The dose of this so-called lupulin is 2-5 grains. From it there is prepared the Tinctura Lupulinae of the United States pharmacopoeia, which is given in doses of 10-60 minims. Furthermore, there are prepared hop pillows, designed to procure sleep; but these act, when at all, mainly by suggestion. The pharmacological action of hops is determined first by the volatile oil they contain, which has the actions of its class. Similarly the lupulinic acid may act as a bitter tonic. The preparations of hops, when taken internally, are frequently hypnotic, though unfortunately different specimens vary considerably in composition, none of the preparations being standardized. It is by no means certain whether the hypnotic action of hops is due to the alkaloid lupulin or possibly to the volatile oil which they contain. Medical practice, however, is acquainted with many more trustworthy and equally safe hypnotics. The bitter acid of hops may endow beer containing it with a certain value in cases of impaired gastric digestion, and to the hypnotic principle of hops may partly be ascribed—as well as to the alcohol—the soporific action of beer in the case of some individuals.

The cultivation of hops in the British Isles is restricted to England, where it is practically confined to half-a-dozen counties—four in the south-eastern and two in the west-midland districts. In 1901 the English crop was reported by the Board of Agriculture to occupy 51,127 acres. The official returns as to acreage do not extend back beyond 1868, in which year the total area was reported to be 64,488 acres. The largest area recorded since then was 71,789 acres in 1878; the smallest was 44,938 acres in 1907. The extent to which the areas of hops in the chief hop-growing counties vary from year to year is sufficiently indicated in Table I., which shows the annual acreages over a period of thirteen years, 1895 to 1907. The proportions in which the acres of hops are distributed amongst the counties concerned vary but little year by year, and as a rule over 60% belongs to Kent.

—Hop Areas of England 1895 to 1907. Acres.

Less than 200 acres in all are annually grown in the other hop-growing counties of England, these being Shropshire, Gloucestershire and Suffolk.

The average yield per acre in cwt. in the six counties during the decade 1897 to 1906 was as follows:—

Table. shows the average acreage, yield and total home produce of England during the decades 1888–1897 and 1898–1907.

The wide fluctuations in the home production of hops are worthy of note, as they exercise a powerful influence upon market prices. The largest crop between 1885, the first year in which figures relating to production were collected, and 1907 was