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. In reviewing these various products gathered or elaborated by bees, we cannot fail to be struck with the marvellous adaptation of different materials to the wants of the community, the skill displayed in the application of them to the general purposes of the commonwealth; and, above all, the wondrous suitability of means to ends, shown by the workers of the hive. If we refuse to allow the possession of reason to these extraordinary insects, we must admit the existence in them of some faculty almost more to be admired; and, in any case, we can but bow in reverence before the all-comprehensive Divine wisdom and goodness, which have endowed creatures so small with powers so surprising which have made them subservient to human needs or comfort, and which have enabled the bees to work even to better advantage under the tutelage of man, than when left to their natural habits and surroundings. CHAPTER XI. PHYSIOLOGY OF THE BEE.