**Essay**, or **Say**, in Metallurgy, the proof or trial of the goodness, purity, value, &c. of metals and metallic substances. See **Essay**.

In ancient statutes this is called **touch**; and those who had the care of it, **keepers of the touch**.—Under Henry VI, divers cities were appointed to have touch for wrought silver-plate, 2 Hen. VI. c. i.5.—By this, one might imagine they had no better method of assaying than the simple one by the touch-flone; but the case is far otherwise. In the time of King Henry II., the bishop of Salisbury, then treasurer, considering that though the money paid into the king's exchequer for his crown-rents did not answer **numero et pondera**, it might nevertheless be mixed with copper or brass: wherefore a constitution was made, called the **trial by combustion**; which differs little or nothing from the present method of assaying silver. See a description of it in the Black Book in the Exchequer, written by Gervase of Tilbury, c. xxi. This trial is also called **efluum**, and the officer who made it is named **floris**. The method still in use of assaying gold and silver was first established by an act of the English parliament 1354.

**Assaying**, **ars docimastica**, in its extent, comprehends particular manners of examining every ore, or mixed metal, according to its nature, with the best-adapted fluxes; so as to discover, not only what metals, and what proportions of metal, are contained in ores; but likewise how much sulphur, vitriol, alum, arsenic, finely, &c. may be obtained from every one respectively. See **Mineralogy Index**.

Assaying is more particularly used by moneyers and goldsmiths, for the making a proof or trial by the cuppel, or teit, of the fineness or purity of the gold and silver to be used in the coining of money, and manufacture of plate, &c. or that have been already used therein.

There are two kinds of assaying; the one before metals are melted, in order to bring them to their proper fineness; the other after they are struck, to see that the species be standard. For the first assay, the assayer is used to take 14 or 15 grains of gold, and half a drachm of silver, if it be for money; and 18 grains of the one, and a drachm of the other, if for other occasions. As to the second assay, it is made of one of the pieces of money already coined, which they cut in four parts. The quantity of gold for an assay among us is six grains; in France nearly the same; and in Germany, about three times as much.

The proper spelling of that word, however, is **es-say**; under which article, therefore, the reader will find the subject more particularly treated.

**Assay-Balance**, or **Effay-Balance**. The flat pieces of glass often placed under the scales of an assay-balance, seem, by their power of electricity, capable of attracting, and thereby making the lighter scale preponderate, where the whole matter weighed is so very small. See **Effay-Balance**.

The electricity of a flat surface of about three inches square has been known to hold down one scale, when there were about 200 grains weight in the other. See **Balance**.

**Assay-Master**, or **Effay-Master**, an officer under certain corporations, intrusted with the care of making true touch, or assay, of the gold and silver brought to him; and giving a just report of the goodness or badness thereof. Such is the assay-master of the mint in the Tower, called also **effayer of the king**.

The assay-master of the goldsmith's company is a sort of assistant-warden, called also a **touch-warden**, appointed to survey, assay, and mark all the silver work, &c. committed committed to him. There are also assay-masters appointed by statute at York, Exeter, Bristol, Chester, Norwich, Newcastle, and Birmingham, for assaying wrought plate. The assay-master is to retain eight grains of every pound troy of silver brought to him; four whereof are to be put in the pix, or box of deal, to be re-assayed the next year, and the other four to be allowed him for his wafte and spillings.

Note. The number of pennyweights let down in the assay-master's report, is to be accounted as per pound, or so much in every pound of 12 ounces troy. For every 20 pennyweight, or ounce troy, the silver is found by the assay to be worse than standard, or sterling, sixpence is to be deducted; because every ounce will cost so much to reduce it to standard goodness, or to change it for sterling.

In gold, for every carat it is set down to be worse than standard, you must account that in the ounce troy it is worse by so many times 3s. 8d.; and for every grain it is set down worse, you must account it worse by so many times 1½d. in the ounce troy; and for every half grain 5½d.: so much it will cost to make it of standard goodness, &c.

Asselyn, John, a famous Dutch painter, was born in Holland, and became the disciple of Isaiah Vanderselde the battle-painter. He distinguished himself in history-paintings, battles, landscapes, animals, and particularly horses. He travelled into France and Italy; and was so pleased with the manner of Bamboccio, that he always followed it. He painted many pictures at Lyons, where he married the daughter of a merchant of Antwerp, and returned with her to Holland. Here he first discovered to his countrymen a fresh and clear manner of painting landscapes, like Claude Lorraine; upon which all the painters imitated his style, and reformed the dark brown they had hitherto followed. Asselyn's pictures were so much admired at Amsterdam, that they sold there at a high price. He died in that city in 1660. Twenty-four pieces of landscapes and ruins, which he painted in Italy, have been engraved by Perelle.