Honey

Honey now claims our attention. It is a common ingredient in moist water-colours, and was often employed in size-painting. It is used to counteract the brittleness of gum or of size when dry, or, by its absorption and retention of water, to keep a paint moist. Honey consists of nearly equal quantities of two sugars known as dextrose and laevulose, a little sucrose or common sugar, small quantities of non-saccharine compounds, and about 20 percent of water. As the useful properties of honey depend entirely upon its laevulose, a solution of this sugar should be employed instead of the raw honey: this may be easily prepared in the following way: Pure pale honey, kept until it has become crystalline and semi-solid from the separation of dextrose, is mixed gradually with four times its bulk of proof spirit, and thoroughly shaken at intervals for a few hours. The pale yellow alcoholic solution is then filtered: the filtrate is a solution of laevulose, accompanied by small quantities of the other sugars of honey and of harmless impurities, and for some artistic urposes is at once available.

Should it be desired to obtain a more concentrated solution of this substance, the liquid may be evaporated to the desired consistency in a porcelain basin, or it may be submitted to distillation in a retort. The aqueous solution of laevulose may be decolourized by filtration through warm animal charcoal.

laevulose, when free from water, forms a glassy solid; but it is usually obtained as a thick syrup. Although this sugar is capable of assuming the crystalline form, it never does so under ordinary conditions. It has a strong attraction for moisture; on this property its usefulness as a constituent of certain paints depends.