The works of the highly experienced and famous chymist, John Rudolph Glauber

by Johann Rudolf Glauber

A Lute for the erecting of Furnaces.

Lute may be made divers wayes for this business; for men prepare their Lute several wayes as they please. Some mix with sifted Potters earth, the beaten hairs of Cows, Oxen, Harts, or the chaffe of Barley, Tow, Flocks, Horse dung, and the like, that hold together the clay, and prevent chops, to which they add sometimes sifted sand, if the clay be too fat, beating the mixture together with water, and bringing it to a just consistence. And this is the best mixture, that is not subject to cleaving, yet weak, because in length of time the hair and chaffe are burnt, wherefore the Furnace becomes thin and weak. Many leave out combustible things, and mix Potters clay, and sand together, and temper them with brine, for the making of their Furnaces. And this is the best mixture, because it is not combustible as the other is, neither is it subject to cracking, by reason of the salt: and for this purpose, the brine of fish and salt flesh doth serve, and is very good, because the blood helps the joining of them together: but if the Caput mortuum of vitriol or Aqua fortis, being mollifyed, be mixed with Potters clay and sand, you go a better way to work: for this Lute is not at all subject to cracking, but fixed in the fire and permanent. With this Lute are Retorts, and Gourds very well luted, and coated, also the joints of Retorts, and Receivers closed: this being mollifyed with a wet cloth applyed to it, may again be separated, and taken off, as that also with which salt is mixed: but the other Lutes that want salt will not be separated, by reason whereof glasses oftentimes are broken. Wherefore in defect of the Caput mortuum of Vitriol, temper the clay and sand with brine: But many mix the filings of iron, powdered glass, flints, &c. but you need not them for the building of the Furnaces, but only for the coating of certain glasses used for separation, and distillation, because the filings of iron being helped with salt, binds, and joins together most strongly.

Of the closing of the Joints, hindering the evaporation of subtle Spirits.

The aforesaid Lute is sufficient for the closing of the Joints of the first Furnace, where air is not kept from the Spirits, but not of the Vessels of the second Furnace, where most subtle Spirits are distilled, which it cannot retain, penetrating the same with the loss of the better part: wherefore you must make choice of another; unless upon the other being well dryed, a mixture made of quick Lime, most subtilly powdered, and Linseed-oyl, besmeared over with a pencil, which the porous clay attracting to it, is fortifyed, so as to be able to retain those most subtle Spirits: but this Lute can hardly be separated again; because refusing water, it cannot be mollifyed; wherefore the clay is to be tempered only with the white of eggs, and to be applyed with linnen clouts: but you must prevent the burning of the linnen, by reason of the extream heat of the neck of the Receiver, by putting between an iron or strong glass, viz. betwixt the receiver and the retort. The joints also may be closed with oxe bladders wet in the white of eggs, also with starch tempered with water, if it be sometimes applyed, being smeared on paper. For by this means those most subtile spirits are easily retained, but not corrosive, for which use the caput mortum of aqua fortis is more convenient which after it is dryed must be smeared over with a mixture made of linseed oyl, and quick lime.

And divers kinds of these lutes are had being destined to divers uses.

Another Lute for broken Glasses.

It happens sometimes that glass vessels, as receivers, and retorts, have some cracks, but otherwise are whole and sound; which are greater in those glasses that do again suffer the heat of the Fire, wherefore at last the glasses are broken, which if you will prevent, make a liniment or thin lute of linseed oyl, quick lime, and red lead; which being smeered over a linnen cloth apply to the crack, upon which being dryed apply another: but if the crack be very great, you may apply three or four linen cloths, for the greater safety sake: as you may apply the whites of egges beaten together, upon the cracks with linnen, and cast upon it quick lime sifted very fine, and press it down hard with your hand: which being done, you may apply over them more linen clouts wet in the whites of eggs, and cast upon them quick lime again: which when the lute is well dryed, retaines the spirits, but sooner subject to the corrosion of corrosive spirits than the former.

Note well that quick lime is not to be mixed with the white of eggs, and so used upon linen clouts, as the manner of some is; because the whites of eggs acquire a hardness from the lime before they be united, and therefore cannot stick, but linen clouts wet First therewith before the quick lime be cast upon them, so that the lime doth not immediately touch the glass, being applyed betwixt two linen cloths.

How those subtile spirits when they are made, may be kept that they evaporate not.

Those glasses in which those spirits are kept are for the most part stopt with cork, or wax, upon which afterward bladders are bound: which stopping is convenient for some spirits, that do not prey upon cork or wax: For all corrosive spirits, as of vitriol, Allome, common salt, nitre, &c. corrode cork, and lixivial spirits, as that of harts-horn, tartar, salt armoniack, urin, wine, &c. melt wax, and penetrate it.