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._