252. _Glue to hold against Fire or Water._--Mix a handful of quick-lime in four ounces of linseed-oil, boil them to a good thickness, then spread it on tin plates in the shade, and it will become exceedingly hard; but may be easily dissolved over the fire, as glue. 253. _To mend China._--Mix together equal parts of fine glue, white of eggs, and white of lead, and with it anoint the edges of the article to be mended; press them together, and when hard and dry scrape off as much of the cement as sticks about the joint. The juice of garlic is another good cement, and leaves no mark where it has been used. 254. _Cement and Ground Glass Imitation._--In half-a-pint spirits of wine steep one ounce of isinglass twenty-four hours, then dissolve it over a slow fire, keeping the vessel covered that the spirit may not evaporate (for this purpose a double saucepan should be used, the outer one containing water, after the manner of a glue-pot; or the solution may be made in a jar with a lid, tied over also with bladder, and placed in a saucepan of water--the water should surround the jar to the height of two inches or more, but not so high as to float it). When the isinglass is completely dissolved, add the juice of garlic, obtained by pounding in a mortar six cloves of the root, and straining through linen. Mix well, and cork close for a short time. The mixture will then cement either glass or crystal. 254a. _Cement to resist Fire and Water._--Half-a-pint each of vinegar and milk, simmer them together till the curd separates. Strain, and with the whey mix the whites of five eggs well beaten up. The mixture of these two substances being complete, add sifted quick-lime, and make the whole into the consistence of putty. Let it be carefully applied--that is, to lay it on every part of the broken edges, and to make the edges fit exactly; as soon as it is perfectly dry, it will be found to resist both heat and moisture. Whatever the article was originally calculated to bear, it is again fitted to bear as much as if it had never been broken. 255. _To imitate Ground Glass._--Rub the glass over with a lump of glaziers' putty, carefully and uniformly until the surface is equally covered. This is an excellent imitation of ground glass, and is not injured by rain or damp. It is useful for kitchen windows, &c.