Dictionarium Polygraphicum. Amber.

Dictionarium Polygraphicum:
Or, The Whole Body of Arts Regularly Digested.
Vol I.
London: Printed for C. Hitch and C. Davis in Pater-noster Row, and S. Austen in St. Paul's Church Yard. MDCCXXXV.
Amber, is a yellow, transparent substance, of a gummous and bituminous form and subsistence; but a resinous taste, and a smell like oil of turpentine.

It is chiefly found in the Baltick sea; along the coasts of Prussia, &c.

Naturalists differ widely in their opinions as to the origin of Amber, and as to what class of bodies it belongs. some supposing it to proceed from vegetables, others from a mineral, and even some from animals.

Pliny describes it as a resinous juice oozing from aged pines and firs, others from poplar trees (of which there are whole forests on the coasts of Sweden;) and discharg’d thence into the sea; where having undergone some alteration it is thrown in this form upon the shores of Prussia, which lie very low. Some have imagin'd it a concretion of the tears of birds; others the urine of beasts, others the scum of the lake Cephiside near the Atlantick; others a congelation form'd in the Baltick sea, and in some fountains, where it is found swimming like pitch.

Others suppose it a bitumen, trickling into the sea from subterraneous sources; there concreted into this form, and thrown ashore by the waves.

This last opinion was for a long time most popular, and seem'd to have the best foundation: but this too is now dis carded, as good amber having been found in digging the ground, at a considerable distance from the sea, as that gathered on the coasts.

Others take Amber to be a compound substance, and say that Prussia and other countries that produce Amber, are moistened with a bituminous juice, which mixing with the vitriolick salts abounding in those places, the points of those salts fix its fluidity, whence it congeals; and the result of that congelation makes what we call Amber.

The most remarkable property of Amber, is that when rubb'd, it draws or attracts other bodies to it, and also, that by friction it is brought to yield light pretty copiously. As for the physical uses of Amber, it is us'd in making varnishes for several uses.

To make artificial Amber. Boil turpentine in an earthen pot, with a little cotton (some add a little oil) stirring it, till it is as thick as paste, then put it into what you please, and set it in the sun for eight days, and it will be clear and hard: of which you may make beads, hafts of knives or the like.

Another way to counterfeit Amber. Take the yolks of sixteen eggs; beat them well with a spoon; take gum Arabick twelve ounces, cherry tree gum one ounce, reduce the gums to powder, and mix them with the yolks of the eggs; let the gums melt well and put them in a pot well leaded, then set them for six days in the sun, and they will be hard and shine like glass; and when you rub them, they will take up a wheat straw as other Amber does.

Another artificial Amber. Take whites of eggs; beat them well, then put them into a vessel with strong white wine vinegar, stop it close; let it stand fourteen days, then dry it in the shade and it will be like Amber.

Another artificial Amber. Break the whites of eggs with a spunge, take off the froth, to the rest put saffron, put all into a glass close stopp'd or into a copper or brazen vessel, set it to boil in a kettle of water, till it be very hard, then take it out and shape it to your liking, lay it in the sun and anoint it often with linseed oil, mix’d with a little saffron; or else being taken out of the kettle, boil it in linseed oil.

To make yellow Amber soft. Put yellow Amber into hot melt ed wax well scumm’d, and it will be soft, so that you may make things thereof of what form and fashion you please.

Melt some turpentine in a glass in a sand heat, where the fire may be rais'd at discretion, then provide your self with three ounces of Amber, either of the whitest or yellowest sort.

If you would have the Amber white, pick out the clearest white pieces, or if yellow the clearest of that sort.

To melt Amber and cast it into any figure, with flies or any finall animals in it, as is seen in those valuable pieces of Amber sold at a great price, from Mr. Boyle.

Levigate your Amber, and sprinkle in the powdered Amber into the melted turpentine, stirring it all the while with a piece of fir-wood, till you find no resistance; then if you find your melting to resist the stick, drop in by degrees a little Venice Turpentine, and keep it still stirring, till all the powdered Amber is dissolv’d, and is thick enough to pour into moulds; and when it is cold, you will have what figure you propose remain as hard as amber itself, with all the same qualities that amber commonly has.

An Amber varnish from Mr. Boyle. Take of white rosin four drams, melt it in a clean glaz'd pipkin, then put into it two ounces of the whitest Amber you can get (finely powder'd) by little and little, stirring it with a small stick over a gentle fire, till it dissolves, pouring in now and then a little oil of turpentine; when you find it begin to grow stiff, so continue to do till all the Amber is melted.

But great care must be taken that you do not set the house on fire, for the very vapours of the oil of turpentine will take fire by heat only; but if it should happen to do so, imme diately cover the vessel close with a flatboard or a wet blanket, and the air being kept from it, it will go out.

It will be best to melt the rosin in a cylindrical glass in a bed of hot sand, after the glass has been well anneal’d or warm'd by degrees in the sand; under which you must keep a gentle fire.

When the varnish is made, pour it into a coarse linen bag, and press it between two hot boards of oak or iron, and use it with any of your colours, as well as to varnish them over when they are painted.

Ei kommentteja :