Wax.—Wax is a vegetable product, deriving its origin from the saccharine principle existing abundantly
—"The honey-dew was noticed by the ancients, and is mentioned by Pliny by the fanciful designation of 'the sweats of the heavens,' and 'the saliva of the stars,' though he questioned whether it is not a deposition from the air, purging this from some contracted impurity. More modern philosophers have been quite as erroneous and discordant in their opinions relative to its nature. Some, with the most unmitigable asperity, declare that it is the excrement of aphides; others as exclusively maintain that it is an atmospheric deposite; and a third party consider that it arises from bleeding consequent to the wounds of insects. That there may be a glutinous saccharine liquid found upon the leaves of plants, arising from the first and third named causes, is probable, or rather certain; but this is by no means conclusive that there is not a similar liquid extravasated upon the surface of the leaves, owing to some unhealthy action of their vessels. It is with this description of honey-dew that we are here concerned. The error into which writers on this subject appear to have fallen, consists in their having endeavoured to assign the origin of every kind of honey-dew to the same cause." After noticing the theories of White and Curtis, the writer goes on to say, "The various successful application of liquids to plants, in order to prevent the occurrence of honey-dew, and similar diseases, would seem to indicate that a morbid state of the sap is the chief cause of the honey-dew: for otherwise it would be difficult to explain the reason why the use of a solution of common salt in water, applied to the soil in which a plant is growing, can prevent the appearance of a disease caused by insects. But if we admit that the irregular action of the sap is the cause of the disorder, then we can understand that a portion of salt, introduced into the juices of the plant, would naturally have a tendency to correct or vary any morbid tendency, either correcting the too rapid secretion of sap, stimulating it in promoting its regular formation, or preserving its"
