The Engineer's and Mechanics Encyclopædia: Wax.

The Engineer's and Mechanics Encyclopædia,
comprehending practical illustrations of the machinery and processes employed in every description of manufacture of the British Empire.
With nearly Two Thousand Engravings.
By Luke Hebert, civil engineer, edifor of the History and Progress of the Steam Engines, Register of Arts and Journal of Patent Inventions, etc.
In two volumes.
VOL. II.
London: Thomas Kelly, 17, Paternoster Row.
MDCCCXXXVI (1836).
An oily concrete matter, usually considered to be gathered by bees from plants; though Huber, who was a close observer of nature, and the habits of bees in particular, asserts that wax is an artificial production, made by the bees from the honey they collect; that they cannot procure it, unless they have honey or sugar for the purpose; and that raw sugar affords more than honey. Wax was long considered to be a resin, from some properties which it possesses in common with resins. Macquer found that wax resembles resin only in being an oil, rendered concrete by an acid; but that it differs essentially from these in the kind of the oil, which, in resins, is of the nature of essential oils, while in wax, and other analogous oily concretions, (as butter of cocoa, butter of milk, fat of animals, spermaceti, myrtle wax,) it is of the nature of mild unctuous oils, that are not aromatic, and not volatile, and are obtained from vegetables, by expression. Dr. Ure considers it probable, that the acidifying principle, or oxygen, and not an actual acid, may be the leading cause of the solidity, or low fusibility of wax; but it has been observed, that by digesting the nitric or muriatic acid upon fixed oils, the oils pass into a state resembling wax. The natural colour of wax is yellow, and it is whitened by exposure, in thin laminae, to the air and sun. Alkalies dissolve wax, and render it miscible in water. In China and North America, wax is procured directly from plants, and is then called vegetable-wax. In order to obtain bees' wax in a pure state, what remains of the combs, after separating the honey, is put into a copper, with a quantity of water, which is made to boil over a slow fire, and stirred frequently with a stick. When the wax has been thus thoroughly melted, it is strained through canvas bags, and the residue in the bags is forced out by a press, whilst hot, and received into a vessel of water. When all the wax has been thus cleared of the grosser impurities, it is again melted over water, and the scum which arises in the boiling is carefully skimmed off'; after which, it is poured into pans or moulds of the size required, to solidify. Wax keeps better in large cakes than small ones: any sediment that may remain at the bottom of the cakes is scraped off before bleaching.

The ordinary process of bleaching wax, consists in first melting it at a low heat, in a cauldron, from whence it is allowed to run out by a pipe at the bottom, into a capacious vessel filled with cold water, in which is fitted a large wooden cylinder, that is made to turn round continually on its axis, upon which the melted wax falls. The surface of the cylinder being constantly wet, the wax does not adhere to it, but lays solid and flat, acquiring the form of ribbands. The continual rotation of the cylinder carries off these ribbands as fast as they are formed, and distributes them through the tub. The wax is then put upon large frames covered with linen cloth, which are supported about eighteen inches above the ground, in situations exposed to the air, dew, and the sun. The thickness of the several ribbands, thus placed upon the frames, ought not to exceed an inch and a half, and they ought to be removed from time to time, in order that they may all be equally exposed to the action of the air. If the weather be favourable, the colour will be changed in a few days. It is then to be re-melted, formed into ribbands, and exposed to the air as before. These operations are to be repeated, until the wax is rendered perfectly white; after which it is to be melted into cakes, or formed into candles.

Of late years, the sulphuric acid, and other chemical agents, have been proposed for shortening the process of bleaching wax, but we are inclined to believe that they have not been successfully carried into practice, as the manufacturers, we are informed, adhere to the old process above described. To what extent chlorine has been applied to this purpose, or in what manner, we are not informed; but the process employed by Mr. Davidson, of Glasgow, and recently patented by him, is stated, in the specification, to be as follows: —

"The wax or tallow is heated to about the temperature of boiling water, in an iron vessel lined with lead, when the oxymuriate of lime, (chloride of lime,) or the oxymuriate of magnesia, (chloride of magnesia,) is to be added, either in solution with water, or in the dry state, and then intimately mixed and well stirred up with a wooden spatula. When these materials have acted upon each other a sufficient length of time to discharge the colour from the wax or tallow, the lime or magnesia is to be removed, by adding dilute sulphuric acid, or some other acid possessing a greater affinity for those earths than chlorine. The whole is then to be boiled, until the earth employed is separated."

For the bleaching of wax, the solution of the chloride is to be in the proportion of from 14 to 28 pounds of the salt, to 1 1 2'pounds of water; and an equal quantity by weight, of the solution and of the wax, to be employed in the process. The sulphuric acid should be of the specific gravity 1.8485, and be diluted with from twenty to thirty times its weight of water.

For the bleaching of tallow, a solution of chlorine, of less strength than the above, will suffice, and the sulphuric acid should be more plentifully diluted: but the proportions necessary, will vary both in the wax and the tallow, according to the quantity of colouring matter that may be combined with them. The following formulae for the composition of the various kinds of sealing-wax, will not be out of place: —

The best hard red wax for sealing letters
Mix two parts of shell-lac, well powdered, with resin and vermilion, each one part, and melt this combined powder over a very gentle fire: when the ingredients are thoroughly incorporated, work the mass into sticks. Seed-lac may be substituted for shell-lac; and instead of resin, boiled Venice turpentine may be used.

Coarse hard red sealing-wax
Mix two parts of resin, one part of shell-lac, vermilion and redlead together one part; the latter in the proportion of one of vermilion to two of the red-lead. For a cheaper kind, the vermilion may be omitted, and fur very coarse uses, the shell-lac also.

Black sealing-wax is made in the same manner as red, with the exception of the colouring; the colouring ingredient for black wax, being the finest ivory black.

Hard green sealing wax is the same mixture of resins and gum-resins as before-mentioned; the colouring ingredient is powdered verdigris; for a brighter colour, crystals of verdigris.

Blue sealing-wax
Use smalts, light blue verditer, or a mixture of both.

Yellow sealing-wax
Use massicott; for a fine bright yellow, turbith mineral.

Purple sealing-wax
Use half vermilion, and half smalts, or red and blue in various proportions, according to the tint required.

Particular attention should be paid to the ingredients, while over the fire, that no more heat be given than is just sufficient for them to melt, and be thoroughly incorporated. The wax is formed into sticks, by rolling it on a copper plate or stone, with a rolling-board lined with copper or tin, into rolls of any required size. The polish or gloss is given afterwards, by placing the sticks of wax over a fire in a small stove, which is provided with a suitable apparatus for placing and turning them in that situation, where the heat given to them is just sufficient to melt the surface of the wax, and produce the gloss.

A patent was recently taken out by Mr. Wason, of the Middle Temp.e, for introducing a small wick into the middle of the sticks of wax, for the convenience of sealing letters. These sealing-wax candles we do not, however, perceive in the shops.