With regard to the sting of the bee, Paley aptly remarks that it "affords a beautiful example of the union of chemistry and mechanism: of chemistry in respect to the venom, which, in so small a quantity, can produce such powerful effects; of mechanism, as the sting is not a simple but a compound instrument. The machinery would have been useless, had it not been for the chemical process, by which, in the insect's body, honey is converted into poison; and, on the other hand, the poison would have been ineffectual without an instrument to wound, and a syringe to inject the fluid." CHAPTER XV. THE DISEASES OF BEES. Dysentery: How Produced--Indications--Treatment. Foul-Brood: two kinds--Nature--Propagation. Mr. Cheshire's Discoveries and Treatment--Fatal Effects of Disease--Detection--Vertigo--Analogy of Human and Bee Diseases. How far the diseases of domesticated animals are due to the conditions to which they are subjected by man, and which are always, to some extent, contrary to the natural mode of life of the creatures, we are at present unable to say. We can, however, point with some certainty to cases in which birds and quadrupeds, which are made subservient to our needs or our convenience, suffer in consequence of our treatment. In some degree, this is true with regard to bees. In a wild state their habitations may, indeed, expose them to risks they do not run in hives, but these artificial dwellings, on the other hand, tend to the development, or the extension of, at least two maladies to which their occupants are subject. These are the deadly evils of dysentery and so-called "foul-brood." Dysentery has been known in apiaries from the time of Columella, in the first century of our era, who attributed it to the effect of food derived by the bees from the elm and the spurge. Other more recent writers have ascribed it to over-indulgence in spring-honey, wheresoever derived: others, again, to the consumption of stores which had candied in the cells during the winter. More recent investigations show that there are several means by which this trouble may be generated. In the first place, ineffective ventilation, by permitting the condensation of moisture on the combs, and its admixture with the food stores, is a prolific source of the mischief. During the winter, the low temperature is constantly reducing to a watery condition the aqueous vapour given off by respiration. This vapour, like our own perspiration, contains matter derived from impurities in the circulating fluid, and is the natural vehicle for their removal. If, then, such moisture again enters the body of the bee, it is simply a poison, whose effects become manifest by producing diarrhœa, distension of the abdomen, and more or less speedy death.