This section is from the book "A Text Book Of Materia Medica, Being An Account Of The More Important Crude Drugs Of Vegetable And Animal Origin", by Henry G. Greenish. Also available from Amazon: A Text Book of Materia Medica : Being an Account of the More Important Crude Drugs of Vegetable and Animal Origin.
The nectar secreted by the nectaries of numerous flowers contains as its principal constituent cane-sugar (sucrose). This nectar is sucked up by the bee through an air-tight tube formed from its ligula and labial palps. It is carried through the oesophagus into the crop or honey-sac, becoming mixed on its way with the salivary secretion from special glands. During its stay in the honey-sac, the sucrose of the nectar is converted into invert-sugar (dextrose and levulose) by the enzyme, invertase, which is contained in the salivary secretion. Arrived in the hive, the bee empties the honey-sac by regurgitation into a cell of the honeycomb. From the cells of the honeycomb the honey is separated by cutting and draining, or by centrifugation, or by pressure with or without heat.
Some quantity of honey is produced in England, but the chief sources of supply are California, Chili, and Jamaica.
Honey, when fresh, is a viscous, transparent liquid, becoming semi-solid on standing from crystallisation of the dextrose contained in it. It varies in colour from nearly white to reddish brown. It has an agreeable odour and a sweet, slightly acrid taste, both odour and flavour being to a great extent dependent upon the nature of the flowers from which the nectar was collected.
Pure honey consists chiefly of dextrose and levulose together with water in which these are at first dissolved. It also contains small quantities of volatile oil, formic acid, sucrose, dextrin, proteids, wax, pollen grains, and often fragments of dead insects, etc. It yields from 0'3 to 0.8 per cent. of ash containing traces only of sulphate and chlorides, and usually exhibits slight dextro- or laevorotation (+ 3° to - 3°).
Honey is largely used as a demulcent and sweetening agent as well as for its nutritive properties.
Honey obtained from heather and clover is considered to have the finest flavour, while that from Coniferous plants and species of Eucalyptus is the least agreeable. Some indication of the source of the honey may be obtained from the identity of the pollen grains contained in it. Jamaica honey is often dark in colour, while Australian honey usually has an unpleasant eucalyptus flavour.
The most common adulterants are sucrose and commercial glucose both of which produce dextrorotation in the honey. The presence of calcium sulphate, which may be tested for in the usual way either in the honey or in the ash, indicates commercial glucose. Pure honey should show at most a slight turbidity when mixed with three or four volumes of alcohol (absence of dextrin, a frequent constituent of commercial glucose).