In extracting honey from combs by pressure, it is well to avoid any admixture of the bee-bread, as its taste is by no means a pleasant addition to the flavour of the sweet liquid. By using any of the "extractor" machines now in vogue, all danger of having the pollen mingled with the honey is avoided. CHAPTER X. PROPOLIS. Derivation of Word--Sources--Nature--Purposes--Quantity Collected--Adaptation of Materials to Wants of Bees. Another substance carried in, and largely used by the bees, is an exceedingly sticky material called propolis, from two Greek words signifying "before the city," as it was observed, in early times, that it was employed in strengthening the outworks of their fortress-home, or, at least, in firmly securing the rim of their hives to their floor-boards. It was formerly a matter of considerable discussion whether this substance was a natural vegetable product, or whether it was elaborated, as wax is. There is now little doubt that it is chiefly a sort of resin derived from plants, and especially from the leaf-buds of certain kinds, like the horse-chestnut, the alder, birch, willow, and hollyhock. Huber, to whom we are indebted for so many interesting and careful observations on apiculture, tried the experiment of placing in pots branches of the poplar, before the buds had opened, and these he put near his apiary. The bees, settling on them, separated the folds of the largest buds, extracted the resinous matter in threads, loaded it on their thighs, as they do pollen, and carried it to their hives. In the spring one may often notice a loud humming round the foliage of deodars, firs, and other coniferæ; and some wonder may, at first, be felt as to what the busy insects can want from such absolutely honeyless trees. When we remember the turpentinous exudations which are so abundant in these cone-bearers, all difficulty disappears. It is for supplies of propolis the workers are searching. Evans says on this subject:-- "With merry hum the willow's copse they scale, The fir's dark pyramid, or poplar pale; Scoop from the alder's leaf its oozy flood, Or strip the chestnut's resin-coated bud, Skim the light tear that tips Narcissus' ray, Or round the hollyhock's hoar fragrance play." It is most probable that, with the resinous substances collected from trees, they knead up a certain proportion of wax, to increase the tenacity. The resulting product is one of extraordinarily glutinous quality. With it the bees stop every chink and crack and cranny in their abodes. With it they stick down skeps to floor-boards, fasten, if they can, frames to the top of bar-hives, firmly fix the combs to their points of attachment, strengthen weak places in their dwellings, and, in some cases, where glass has been inserted in the walls of hives for observation purposes, the panes are found completely coated with propolis, so as to exclude the light.