Honey appears to consist mainly of two kinds of sugar, one of which is closely allied to that contained in the grape, and which by spontaneous change is apt to crystallise in contact with air. The other is uncrystallisable, like the purest treacle, and mingled with it are slight quantities of colouring matter and mucilage. These sugars are somewhat apt to undergo a vinous fermentation, of which advantage has been taken in the manufacture of mead--a drink much used by the inhabitants of these islands in ancient times as a stimulant, and even intoxicant. The taste of honey varies according to the flowers or other sources from which it has been chiefly derived. That procured from flowers, especially those of the labiate family--from the clovers, the lime-blossoms, and the heaths--is most esteemed. That which has been derived from sugar-syrup differs but slightly from the liquid of its origin. That procured from what is called honey-dew, or the secretion of various sorts of aphides, is very worthless in quality, though bees are extremely fond of the liquid. It is a remarkable and unfortunate fact, that the honey collected from certain flowers is, though innocuous to bees, more or less injurious to the human body. Xenophon tells us in his _Anabasis_ that his soldiers found many hives in the neighbourhood of Trebizonde, and, after eating of the contents, the men were seized with violent purging and vomiting, stupefaction, and inability to stand. Those who ate little became like men very drunk, and those who ate much, like madmen, and some like dying persons. In this condition great numbers lay upon the ground, as if there had been a defeat. None of them died, and in about twenty-four hours they recovered consciousness. On the third or fourth day after the seizure they got up, but were like men who had taken powerful physic. Tournefort, when travelling in Asia Minor, recollecting these historical circumstances, made careful investigations as to the probabilities of the case. Two kinds of shrubs were pointed out to him as bearing flowers, the honey from which was deleterious, and the very odour of which is still said to produce headache. These plants were the _rhododendron Ponticum_, and _azalea Pontica_, nearly allied species, growing abundantly in that part of the world. Father Lamberti corroborates Xenophon's description, by stating that similar effects have been produced by the honey of Colchis, where these shrubs are common.