account of the loss of the volatile oil. The bitter substance which exists in hops does not appear to decrease, the tannic acid gradually diminishes in quantity; and the volatile principle escapes from the plant and spreads in the atmosphere, or partly oxidizes, which gives the hops a disagreeable odour.

Moreover, hops, like the leafy parts of plants, or the parts of the leaves which are not very thick, when they are exposed to contact with the air, are subject to a species of decomposition which on the Continent has received the name of verwesung. The plant assumes a dark colour, and all its constituent parts are brought more and more into the dominion of chemical transformation. It has been proposed to dry the hops and then to keep them from contact with the air, which would do away with, or at least lessen, two of the conditions which tend to produce a chemical transformation.

Liebig pronounced in favour of sulphuring hops, and he rightly maintained the innocuity of this simple means of preserving a portion of the plant, which, without it, would rapidly enter into decomposition, and which by these means may be transported and preserved, without declining in value or acquiring any injurious property. He cited in support of his opinion the proposition of Braconnot, to preserve, by means of sulphurous acid, the vegetables employed for domestic use, such as chicory, asparagus, sorrel, &c.

Sulphuring.-To preserve the hops they are usually sulphured, that is, subjected to the action of vapours of burning sulphur, 1 lb. to 2 lbs. of sulphur being employed to 1 cwt. of hops. Old hops are sometimes treated in this manner to impart the colour and appearance of freshly dried hops; but the fraud can be detected by the odour. The best method of testing for sulphur in hops is as follows: A sample of the

hops is placed in a sulphuretted hydrogen apparatus, with some zinc and hydrochloric acid; the disengaged gas is passed through a solution of acetate of lead.

If the hops contain sulphurous acid, sulphuretted hydrogen will be disengaged:

(SO2+ 2H2 + 2H2O),

and black sulphide of lead thrown down from the lead solution. Better still is to receive the disengaged gas in a solution of nitroprusside of sodium, to which a few drops of potash ley have been added; the slightest trace of sulphuretted hydrogen imparts a beautiful purple red colour to the solution. (Wagner.)

Insect Depredators.-Although incidental mention has been made in previous pages of the insect scourges of the hop grower, they may here be briefly summarized. Among the insects injurious to the hop are the caterpillars of the ghost moth (Hepialus humuli), which gnaw the roots of the hop plant till the shoots are weakened, and the leaves droop in bright sunshine, the aphides, or plant lice, known as the green fly (Aphis humuli), the plant mite, or red spider (Acarius telarius), and the wireworm. Curtis says the smaller wireworms are very often the larvæ of Elater lineatus and E. obscurus, and the larger ones of E. ruficandis. Hops in Kent, Worcester, and Herefordshire are often reported to be injured by the wireworm. The Rev. E. Sidney, in a lecture on Parasitic Fungi, published in the Journal of the Royal Agricultural Society,' vol. x., p. 394, states that hops are occasionally damaged by an erysiphe, having the habits of that of the pea, which seems to be in its early stage a peculiar mould. The vapour of heated sulphur is usually tried for the red spider, and tobacco water is obnoxious to the aphides.

The scarcity or abundance of the hop crop entirely depends upon the ordinary prevalence or unusual plenty of these pernicious insects. Vain would be the attempt to clear a hop plantation of them, or to rescue any extensive crop from their baneful ravages. Even violent rain has but a partial effect in destroying them.

Production in England.—The growth of hops in Great Britain is almost entirely confined to England, and there chiefly to special localities. The cultivation of this valuable plant does not vary very considerably now from year to year, although affected to some extent by fluctuations of price. Nearly 70,000 acres were returned as planted with hops in England in 1875, the largest acreage ever reached. Hop planting rather declines than otherwise, however, in counties where it is practised upon only a small scale; but the following shows the present acreage and that of seven years previous in the principal districts where it is carried on:

About two-thirds of the acreage under hops, it will be seen, is in the county of Kent. The other counties in which hops

UNIVERSITY

are planted to any extent are Sussex, Hereford, Worcester, Hants, and Surrey.

The number of acres devoted to the cultivation of hops has long been steadily on the increase since 1693, when they were first successfully cultivated in Kent. The Rev. J. Wilkinson, in the 'Journal of the Royal Agricultural Society,' states, but I know not on what authority, that hops were grown in Kent as early as 1464, but did not come into popular use for more than a century. Indeed the acceptability of our bitter beer is a modern and acquired taste. The Royal Brewer of Eltham was enjoined (temp. Henry VII.) to put neither brimstone nor hops into the ale.

It is perhaps worth the consideration of farmers in some counties where hop planting has not hitherto been introduced, whether it ought not to be tried. The opinion of a geologist, Mr. W. Topley, has been published to the effect that "everywhere below the chalk escarpment hops might probably be cultivated with great success, and the Vale of Pewsey, for instance, would seem especially suited for them."

In 1807 it was found that the hop grounds throughout England amounted to 38,218 acres; this gradually increased till 1819, when it reached 51,000 acres; there was then a slight annual retrogression till 1826, when it reached again 50,471 acres; then ensued a check until 1834, when the tide turned once more; and in 1837 the maximum of the

period was reached of 56,323 acres. The same gradual progression and retrogression is noticeable in subsequent years, but in the last nine or ten years the increase has been steady.

The following table gives the acreage under hops officially returned, and the produce per acre, as far as can be ascer

tained. I have not been able to obtain the acreage for

the four years between 1862 and 1866.

Mr. Lance, in his 'Hop Farmer,' makes some slight difference in the average yields up to 1836, but I prefer quoting the above figures, which up to 1853 are upon the authority of Mr. Baxter, of the 'Sussex Express.' The years from 1854 are computed from the official acreage and duty paid. Since the abolition of the duty only conjectural estimates can be made.