This is not the only use to which bees apply the propolis. They are extremely solicitous to remove such insects or foreign bodies as happen to get admission into the hive. When so light as not to exceed their powers, they first kill the insect with their stings, and then drag it out with their teeth. But it sometimes happens, as was first observed by Maraldi, and since by Réaumur and others, that an ill-fated slug creeps into the hive: this is no sooner perceived than it is attacked on all sides, and stung to death. But how are the bees to carry out so heavy a burthen? Such a labour would be in vain. To prevent the noxious smell which would arise from its putrefaction, they immediately embalm it, by covering every part of its body with propolis, through which no effluvia can escape. When a snail with a shell gets entrance, to dispose of it gives much less trouble and expense to the bees. As soon as it receives the first wound from a sting, it naturally retires within its shell. In this case, the bees, instead of pasting it all over with propolis, content themselves with gluing all round the margin of the shell, which is sufficient to render the animal for ever immovably fixed.
Mr. Knight, the learned and ingenious President of the Horticultural Society, discovered by accident an artificial substance, more attractive than any of the resins experimentally tried by Réaumur. Having caused the decorticated part of a tree to be covered with a cement composed of bees'-wax and turpentine, he observed that this was frequented by hive-bees, who, finding it to be a very good propolis ready made, detached it from the tree with their mandibles, and then, as usual, passed it from the first leg to the second, and so on. When one bee had thus collected its load, another often came behind and despoiled it of all it had collected; a second and a third load were frequently lost in the same manner; and yet the patient insect pursued its operations without manifesting any signs of anger.[AN] Probably the latter circumstance, at which Mr. Knight seems to have been surprised, was nothing more than an instance of the division of labour so strikingly exemplified in every part of the economy of bees.