SECRETS FOR BOOK-BINDERS. 249 preserver of the eyes, especially to those that read much by candle light. The varnish must be prepared of linseed oil, and boiled with frankincense, mastich and sandarac. If you would have the parchment of a clear, transpa- rent, and white colour, only wash, strain, and varnish it as above*. If you would colour it yellow, steep your parchment, after it has been washed, in a yellow liquid, made of saffron; for which purpose tic. saffron in a thin linen rag, hang it in a weak lye, and let it warm over a slow fire; and when you see the lye tinctured yellow, it is fit for use. For a Transparent Red. TAKE Brasil-wood, as much as you will; put it into a hot lye, which is clear and not too strong, and it will tincture the lye of a fine red; then pour into it about half an egg-shell full of clear wine; draw the parchment through the colour, and when it is as deep as you would have it, strain it as before. For a Blue. TAKE indigo; grind it with vinegar, on a stone, and mix sal-ammoniac among it, to the quantity of a pea; with this wet your parchment, and proceed as has been directed for the green. * This clear and white transparent parchment, might suit for glazing hot-houses, and cottages, being less liable to break than glass. Eii. For