Book VI. THE HOP. 929 



6054. The vse of the hop in brewing is to prevent the beer from becoming sour. 



6055. In domestic economy the young shoots are eaten early in the spring as asparagus, and are sold 

 under the name of hop-tops. They are said to be diuretic ; and taken in an infusion, to be good against the 

 scurvy. The herb will dye wool yellow. From the stalks a strong cloth is made in Sweden : for this pur. 

 pose they must be gathered in autumn, soaked in water all winter; and in March, after being dried in a 

 stove, they are dressed like flax. They require a longer time to rot than flax, and, if not completely 

 macerated, the woody part will not separate, nor the cloth prove white or fine. Hence a farmer who 

 has a hop plantation need neither grow asparagus nor flax, and may, when the flowers fail from disease 

 separate the fibre from the vine, and employ the poor, or machinery, in spinning and weaving it. A 

 decoction of the roots of hops is considered as good a sudorific as sarsaparilla ; and the smell of the flowers 

 is found to be soporific. A pillow filled with hops was prescribed for the use of George III. in his illness 

 of 1787. 



6056. The hop is peculiarly liable to diseases. There is scarcely any sort of plant 

 cultivated as a field-crop that is more liable to become diseased than the hop. It is apt, 

 in the very early stage of its growth, to be devoured, as it rises above the surface of the 

 ground, by the ravages of an insect of the flea kind. At a more advanced stage, 

 it is subject to the still more injurious effects of the green or long-winged fly, red 

 spider, and otter moth : the first, by the depositing of their ova, afford the means 

 of producing lice in great abundance, by which the plants are often very greatly, 

 if not wholly, destroyed; and the larva? of the last prey upon the roots, and thus 

 render the plants weak and subject to disease. The honey-dew is another disease to 

 which the hop is exposed about the same time, and by which it is often much in- 

 jured. The mould occurs in general at a somewhat later period, and is equally 

 injurious. Hop-crops are also exposed to other injuries, as the blight and fire-blast; 

 but which take place at different times, though mostly towards the latter periods of the 

 growth of the plants. 



6057. The flea, which is said to be an insect of the same kind as that which is so prejudicial to the 

 young turnip, is observed to make the greatest havoc in seasons when the nights are cold and frosty, and 

 the days hot and inclined to be dry ; eating off' the sweet tender tops of the young plants, which, though 

 not wholly destroyed, shoot forth afterwards in a far less vigorous manner, and of course become more 

 exposed to diseases. It has been found to commit its depredations most frequently on the plants in 

 grounds that have been dunged the same year: on which account it has been suggested that the manure 

 employed for the purpose of covering the hills should be previously well mixed and incorporated, as 

 directed above (6019.) ; and that it should be applied either over the whole of the land, or only the hills, 

 as soon as possible after the plants have been cut over ; but the former practice is probably the best. It 

 makes its greatest depredations in the more early, cold, spring months, as the latter end of April and 

 beginning of the succeeding month, disappearing as the season becomes more mild and warm. In these 

 cases, the principal remedy is that of having the land in a sufficient state of fertility, to enable the young 

 plants to shoot up with such vigour and rapidity as to become quickly incapable of being fed upon and 

 devoured by the insect. The frequent stirring of the mould about the roots of the plants with the hoe may 

 be of utility in the same view. 



60.^8. The green or long-winged fly is highly destructive to the young leaves of the plants, and mostly 

 makes its appearance about the latter end of May, and in the two succeeding months ; being ignorantly 

 supposed to be produced by the prevalence of north-easterly winds about that period. Under such a state of 

 the wind, they are said to scarcely ever fail of covering the leaves ; and by dropping their ova, of producing 

 abundance of lice, which often much injure the crops ; as when they have once obtained complete possession 

 of the plants, they seldom or never leave them before they have wholly destroyed them. Insects of this 

 sort generally attack the forwardest and most luxuriant hop-vines. Their removal chiefly depends upon 

 the wind's changing more to the south, and the setting in of more mild, warm, and temperate weather. 



6059. The otter moth, by depositing its eggs upon the roots of the plants, renders them liable to be at. 

 tacked by the larva?, and the healthy growth of the hops is thereby greatly impaired, the crops being of 

 course much injured in their produce. Stirring the earth well about the roots of the plants may probably 

 sometimes be serviceable in cases of this kind. 



6060. The honey-dew mostly occurs after the crops have been attacked by some of these kinds of insects, 

 and when the weather is close, moist, and foggy. In these cases, a sweet clammy substance, which has 

 the taste of honey, is produced upon the leaves of the plants, and they have at first a shining appearance, 

 but soon afterwards become black. It is a disease that mostly happens in the more forward crops; and 

 the chief dependence of the planter for its removal, according to Bannister, is that of heavy thunder 

 showers taking place ; as by this means, when the destruction of the hops has not proceeded too far, they 

 are often much restored, the insects that devour the leaves and vines being greatly destroyed, the growth 

 of fresh shoots promoted, and a favourable bloom brought on the plants. 



6061. The fen, mould, or mildew, is a disease to which the crop is exposed at a later period of its growth, 

 and which chiefly attacks the part where the hop is attached to the stem. It is said that its production 

 is greatly promoted by moist damp weather, and a low situation ; those crops that grow on low, close, rich 

 grounds being most liable to be attacked by it : and it is found to soon spread itself over the whole crop, 

 alter it has once seized upon any part of it. The nature of this vegetable disease has not been yet sufficiently 

 investigated It has been suggested by Darwin and Willdenow to be a plant of the fungus kind, capable 

 of growing without light or change of air, attaching itself to plants already in a morbid condition, and by 

 its roots penetrating their vessels : and on this supposition, the best remedy is believed to be thinning the 

 plants, in order to afford a more free circulation of air, and admit the light more extensively, by which 

 the vigour of the hop-plants may be restored, and the disease be of course removed. In this view, it is 

 probable, by planting the hills more thinly, and making them at gi eater distances from each other, the 

 disease might in some measure be prevented from taking place. (See 169+.) 



6062. Diseases termed blights are frequently met with in hop-crops, at different periods of the growth 

 of the plants, but mostly in the more early stages of their rising from the hills, while the nights are cold 

 and frosty in the spring months, and the days have much sun and heat ; by which the living powers of 

 the plants are greatly exhausted in the daytime by the stimulus of heat, and of course much injured or 

 wholly destroyed in the nights, from being exposed to a freezing air, which is incapable of exciting the 

 actions necessary for the preservation of vegetable life. As the presence of this disease is supposed to be 

 greatly connected with the prevalence of winds from the northern or easterly quarters, there is often a flea 

 produced of a similar kind to that which attacks the shoots in their early growth. (6057.) It is highly in- 

 jurious, by preying upon the nutriment of the blossoms, and thereby diminishing their weight and chang- 

 ing them to a brown colour, which is very prejudicial in their sale at the market. 



6063. The fire-blast is a disease that hop-crops are exposed to in the later periods of their growth, and is 

 generally supposed to proceed from the particular state of the air or weather. Others consider this disease 

 as nothing more than the result of the attacks of the red spider. It has been conjectured to be the effect 

 of lightning, as it takes place, for the most part, at those seasons when lightning is the most prevalent] 



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