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.
In colour, this cement is greenish yellow, darkening with age to brown. Its odour is balsamic and somewhat powerful, resembling that of storax. It was formerly supposed to possess medicinal properties, and was kept in the shop of the apothecary. When smeared on the fingers, it is very difficult of removal. Soap has no effect upon it; water fails to wash it off; but spirits of wine readily dissolve it, and are the most easy and effectual means of getting it off the skin.
Bees usually choose the middle of the day for gathering this substance, as the warmth of the air, by softening the resinous material, facilitates the obtaining of it from the trees, and prevents its too speedy hardening before it reaches the hives. Sometimes, indeed, the resin becomes so firm in consistency by the time the collectors of it get home, that they require the assistance of their fellow-workers to detach it from their thighs.
One very remarkable use to which propolis is occasionally put by the bees, is for the covering up of mice, snails, frogs, or other intruders, whose expulsion is impossible, or who have died after entering the hives. Réaumur relates that, on one occasion, he observed a snail thus glued down to a piece of glass in one of his hives; and, in another instance, where a slug had been stung to death, and was far too large for removal by the insects, these clever sanitarians completely enveloped the mollusc with a coating of propolis-varnish, to prevent the emanation of any noxious vapours when decomposition set in. It was, in fact, a distinct instance of embalming. Huish mentions that a mouse was similarly treated by one of his stocks of bees.
The quantity of propolis collected is sometimes very large, particularly where spaces are left at the top, sides, or bottoms of bee-dwellings. At present, this substance has not been turned to any serviceable human use.