a great measure to realize. The king's jealousy still increasing, she was accused of adultery with several of the household officers, and even with her own brother, Lord Rochfort. She was accordingly tried on a charge of high treason, and although proof was very scanty, yet she was condemned to be beheaded; which sentence was executed in May 1536. Her behaviour on that occasion was a singular mixture of firmness and unusual levity. She avowed being guilty of many excesses, yet to the last resolutely denied any serious guilt. Although her character has been greatly depreciated by several authors, yet a letter written by her to the king after condemnation, gives a much higher idea of her character than these partial accounts would endeavour to convey.
The important part which she and her daughter acted in the Reformation has drawn upon her memory many malignant and vicious stories, by those of the Catholic party, who were likewise induced to this by the expectation of being conducive to the injury of Protestantism, by stigmatizing the various characters and motives of its promoters. These various accounts are, however, for the most part refuted by facts universally known, or have no evidence or probability by which they may be supported. Reflecting her innocence of the charge on which she lost her life, it is a matter of uncertainty, yet it appears to be less certain that she was guilty than that her husband was a bloody and capricious tyrant. (Gen. Biog.)
St Anne's Day, a festival of the Christian church, celebrated by the Latins on the 26th of July, but by the Greeks on the 9th of December. It is kept in honour of Anne or Anna, mother of the Virgin Mary.
Annealing, by the workmen called nealing, is particularly used in making glass; it consists in placing the bottles, &c. whilst hot, in a kind of oven or furnace, where they are suffered to cool gradually: they would otherwise be too brittle for use.—Metals are rendered hard and brittle by hammering: they are therefore made red hot, in order to recover their malleability; and this is called nealing.
The difference between unannealed and annealed glass, with respect to brittleness, is very remarkable. When an unannealed glass vessel is broken, it often flies into a small powder, with a violence seemingly very unproportioned to the stroke it has received. In general, it is in greater danger of breaking from a very slight stroke than from one of some considerable force. One of these vessels will often resist the effects of a pistol bullet dropped into it from the height of two or three feet; yet a grain of sand falling into it will make it burst into small fragments. This takes place sometimes immediately on dropping the sand into it: but often the vessel will stand for several minutes after, seemingly secure; and then, without any new injury, it will fly to pieces. If the vessel be very thin, it does not break in this manner, but seems to possess all the properties of annealed glass.
The same phenomena are still more strikingly seen in glass drops or tears. They are globular at one end, and taper to a small tail at the other. They are the drops which fall from the melted mass of glass on the rods on which the bottles are made. They drop into the tubs of water which are used in the work; the greater part of them burst immediately in the water.
When those that remain entire are examined, they discover all the properties of unannealed glass in the highest degree. They will bear a smart stroke on the thick end without breaking; but if the small tail be broken, they burst into small powder with a loud explosion. They appear to burst with more violence, and the powder is smaller, in an exhausted receiver than in the open air. When they are annealed, they lose these properties.
Glass is one of those bodies which increase in bulk when passing from a fluid to a solid state. When it is allowed to crystallize regularly, the particles are so arranged, that it has a fibrous texture: it is elastic, and susceptible of long-continued vibrations; but when a mass of melted glass is suddenly exposed to the cold, the surface crystallizes, and forms a solid shell round the interior fluid parts: this prevents them from expanding when they become solid. They, therefore, have not the opportunity of a regular crystallization; but are compressed together with little mutual cohesion: On the contrary, they press outward to occupy more space, but are prevented by the external crust. In consequence of the effort of expansion in the internal parts, the greater number of glasses drops burst in cooling; and those which remain entire are not regularly crystallized. A smart stroke upon them communicates a vibration to the whole mass, which is nearly synchronous in every part: and therefore the effort of expansion has little more effect than if the body were at rest; but the small tail and the surface only are regularly crystallized. If the tail be broken, this communicates a vibration along the crystallized surface, without reaching the internal parts. By this they are allowed some expansion; and overcoming the cohesion of the thin outer shell, they burst it, and are dispersed in powder.
In an unannealed glass vessel, the same thing takes place. Sometimes the vibration may continue for a considerable time before the internal parts overcome the resistance. If the vessel be very thin, the regular crystallization extends through the whole thickness; or at least the quantity of compressed matter in the middle is so inconsiderable as to be incapable of bursting the external plate.
By the process of annealing, the glass is kept for some time in a state approaching to fluidity; the heat increases the bulk of the crystallized part, and renders it so soft, that the internal parts have the opportunity of expanding and forming a regular crystallization.
A similar process is now used for rendering kettles and other vessels of cast iron less brittle: of it the same explanation may be given. The greater number of metals diminish in bulk when they pass from a fluid to a solid state; iron, on the contrary, expands.
When cast iron is broken, it has the appearance of being composed of grains: forged or bar iron appears to consist of plates. Forged iron has long been procured, by placing a mass of cast iron under large hammers, and making it undergo violent and repeated compression. A process is now used for converting cast iron into forged, by heat alone. The cast iron is placed in an air furnace, and kept for several hours in a degree of heat, by which it is brought near to a fluid state. It is then allowed to cool gradually, and is found to be converted into forged iron. This process is Annealing is conducted under a patent; although, if Reaumur's experiments upon cast iron be consulted, it will appear not to be a new discovery.
By these experiments, it is ascertained, that if cast iron be exposed for any length of time to a heat considerably below its melting point, the texture and properties are not changed: but if it be kept in a heat near the melting point, the surface soon becomes lamellated like forged iron; and the lamellated structure extends farther into the mass in proportion to the length of time in which it is exposed to that degree of heat. When it is continued for a sufficient time, and then allowed to cool gradually, it is found to possess the lamellated structure throughout.
Cast iron, then, is brittle, because it has not had the opportunity of crystallizing regularly. When it is exposed to cold while fluid, the surface becoming solid, prevents the inner parts from expanding and arranging themselves into regular crystals. When cast iron is brought near to the melting point, and continued for a sufficient length of time in that degree of heat, the particles have the opportunity of arranging themselves into that form of crystals by which forged iron is distinguished, and by which it possesses cohesion and all its properties.
There appears, therefore, to be no other essential difference between forged and cast iron, except what arises from the crystallization. Cast iron is indeed often not sufficiently purified from other substances which are mixed with the calx. It appears also to contain a considerable quantity of calx unreduced; for during the process for converting it into forged iron, by heat alone, a pale flame arises from the metal till near the end of the process. This is owing to fixed air which the heat forces off from the calx. The expulsion of this air reduces the calx, and thereby frees the metal from that injurious mixture.
That this explanation of the annealing of iron is probable, appears also from the well-known fact of forged iron being incomparably more difficult of fusion than cast iron. A piece of forged iron requires a very violent heat to melt it; but when it is reduced to a small powder, it melts in a much lower degree of heat. Iron diminishes in bulk when it passes into a fluid state, while most other metals increase in volume. The expansion which heat occasions in bringing them to their melting point, will be favourable to their fluidity, by gradually bringing the particles to the same state of separation in which they are when the mass is fluid; but the expansion of iron by heat removes it farther from that state, and keeps it in the state which is favourable to the continuance of it in a crystallized form. It will not melt till the heat expand it so much that the cohesion of crystallization be overcome. When it is reduced to a minute powder before it be exposed to the heat, it melts sooner. The crystals having been destroyed, that cohesion has no effect in preventing it from passing into a state of fluidity.
Upon the same principles may be explained the almost peculiar property of welding possessed by iron, and the conversion of forged iron into steel.
But perhaps they may also be applied to platinum, a metal which has lately gained much attention. It possesses some of the properties of iron. It is still more difficult of fusion than that metal. It is susceptible of being welded. The natural grains of it can scarcely be melted in the focus of the most powerful burning glass; but when it is dissolved in aqua regia, and precipitated by potash, it has been melted in small globules by the blowpipe. When precipitated by nitrate of ammonia, it has been melted in a considerable mass in the heat of a furnace; but it is said to be hard and brittle.
Many attempts have been made to procure a mass of it in a malleable state, but without success. It is said that the process is now discovered by a chemist in Spain. The treatment of the metal is probably very simple. Perhaps it only consists in precipitating it in a minute powder from aqua regia, exposing it to a strong heat which melts it, and keeping it for some time in a state nearly fluid, that it may, like iron, crystallize regularly: by this it will possess all its metallic properties.