unite; pass an electric spark through, and water is immediately produced; and this producing a body from its elements is called synthesis.

By putting the negative and positive wires of a sufficiently powerful galvanic battery into water, you may collect from one the 'hydrogen of the water, from the other the oxygen; and this reducing a body into its elements, is called analysis-the water being thus decomposed.

It was by this agent that Sir H. Davy found that soda was composed of a metal called sodium, and oxygen; and that potassa, lime, barytes, &c. in like manner, were formed from metallic bases combined with oxygen ;—the brilliant metal went obediently to one pole, the oxygen was given off from the other. Electricity, then, is a powerful chemical agent.

Magnetism is strongly suspected to be only a variety of electricity.

We can, by chemical decomposition, produce electric matter in abundance, as with copper, zinc, and acid, which we put for this purpose into our galvanic troughs.

In fact galvanism is the production of electrical matter by chemical agency. A number of pieces of zinc 1alternating with as many pieces of copper, and placed in a trough containing water impregnated with nitric or muriatic acid, having also the end plates 1 connected with wires, form a galvanic battery, which will give very violent shocks; and a few of these troughs, simply united by a wire, will kill any animal,-effect many chemical changes, as before referred to, und even inflame the diamond.

1. Vide Root. 2. Polished bodies reflect more, but radiate less; hence a polished tea-pot will keep the tea longer hot than a dull or tarnished one, and a white longer han a black one, even though it be polished. 3. That which dissolves bodies is called the solvent. Water is the great solvent, though not the only one; grease in clothes, for instance, may be dissolved by oil of turpentine, which water would not dissolve. 4. So named from Galvani, an Italian, who first applied electricity to the nerves and muscles of dead animals, and thereby produced action in them.

TURKEY.

THE Tartars having made themselves masters of all the Saracen possessions, adopted the Mohammedan religion, and thus the Turkish empire became the successor of the Saracen empire, and included in its 'dominion Asia Minor, Syria, Palestine, and other Asiatic countries, which the Saracens had conquered from the Greek empire.

Constantinople, the present capital of Turkey, was called Byzantium, from Byzas, who founded it in 715 B.C. It was a flourishing city in the time of the early Greeks. The neighbouring country was settled by 'colonies from Greece, and by other tribes. It was conquered by the Romans, and the name of Byzantium was changed to Constantinople, by the emperor Constantine, in 329.

It had before this period fallen into decay, but it was now revived, and Constantine removed thither with his whole court. It thus became the capital of the Roman empire. When that was divided into the Eastern and Western empires in 395, it was the capital of the former, which was often called the Greek empire.

The Greek or Eastern empire continued, with various changes, to subsist as a distinct sovereignty, till the fourteenth century. It was now on the brink of ruin, and the Ottomans, who had already established themselves in Asia Minor, and swallowed up the countries formerly belonging to the Saracen dominions, began to cast longing eyes upon it.

Bajazet began to reign in 1389, and was so famous for his conquests, that the Turks called him the Thunderbolt. He was preparing to attack Constantinople, when

1. Vide Root.

2. The Turkish government is despotic, the Koran eujoining the most slavish obedience on the subject, and death or conversion to Mahometanism on all foreigners in their power. 3. Mamelukes, a body of foreign cavalry soldiers, intended as a body guard for the sovereign. Subsequently re-established, and destroyed by Mehemet Ali, pacha of Egypt. Pacha, is a title given to governors of provinces.

Tamerlane, otherwise called Timour the Tartar, and sometimes Timour the Lame Man, defeated Bajazet in a great battle, in which three hundred thousand men were slain.

It is said that when Timour the Lame Man had got Bajazet the Thunderbolt into his power, he put him into an iron cage, and carried him about for a show, like a wild beast. Most conquerors have a resemblance to wild beasts, and it would be well if they could always be kept in iron cages.

The misfortunes of 'Bajazet prevented the Turks from conquering the Eastern empire of the Romans, for a considerable time. But in 1453, when Mahomet the Great was sultan, they took Constantinople.

The reigns of most of the Turkish sultans have been full of crime and bloodshed. Sultan Selim, who began to reign in 1512, invaded Egypt and conquered it. The Egyptian soldiers were called Mamelukes.

After the victory, the sultan ordered a splendid throne to be erected on the banks of the river Nile, near the gates of Cairo. Sitting on this throne, he caused all the 3 Mamelukes to be massacred in his sight, and their bodies to be thrown into the river.

1

Amurath the Fourth became sultan in 1621. This monster caused fourteen thousand men to be murdered. Mahmoud the Second ascended the throne in 1808. He was more enlightened than his predecessors, and attempted to introduce European improvements. He died in 1839, and was succeeded by his son, Abdul Medschid.

1

GEOGRAPHICAL.-Area, 500,000 square miles. Population, 12 millions.
How is Turkey bounded?

What are its principal mountains, cities, and rivers?

Write the names of the chief islands belonging to Turkey.

Describe the situation of the following places in Asia Minor:-Tarsus, Troy, and the seven apostolic Christian churches.

CHRONOLOGICAL.-The Tartar tribe called Turks, employed by the Emperor Heraclius, A.D. 625.

The Turks subvert the Saracens, A.D. 1258.

Ottoman, the founder of the Turkish or Ottoman empire, A.D. 1297.
The Turks, under Amurath, cross the Hellespont into Europe, 1357.

CHEMISTRY.

Simple or Elementary Bodies.

THERE is in nature a vast variety of substances, but these are all composed out of a few, which are called simple or elementary. By chemical agency you may 1 extract or detect these simple bodies.

1

The atmosphere consists of three elements-oxygen, nitrogen, and a little carbon, and each of these is simple; that is, it cannot be further decomposed. Water consists of hydrogen and oxygen. There are no two things entering into the composition of hydrogen, it is simple; so of oxygen, you cannot by uniting any two things make oxygen, but you may extract it from water, or from any thing else into the composition of which it enters.

There are about fifty-two of these simple bodies, out of the infinitely-varying 2 union of which, all the vast variety of things are produced. Of course the same simple body enters into combination with many others, producing these differences. Thus oxygen unites with hydrogen, forming water; with nitrogen it forms air; with sulphur it forms oil of vitriol; with the metal calcium it forms lime.

There is however a regular proportion in which bodies unite with each other. Take oxygen for instance-eight parts by weight combine with one by weight of hydrogen; that is, nine pounds of water consist of exactly eight pounds of oxygen and one of hydrogen.

Oxygen always combines in ratio of once eight, or twice eight, or three times eight; and hydrogen as one, or twice one, or thrice one; carbon as once six, or twice six; these numbers are called chemical 'equivalents. Every substance has its equivalent or proportion, in which it combines with others: this is the theory of chemical proportion.

The forms of these bodies are not alike, for some are

gaseous, that is, are like air; some are fluid, as mercury; some are solid, as gold, iron, sulphur.

Gases or aëriform bodies are frequently simple; such is hydrogen, which forms the bulk of the gas used for lighting; such is oxygen, which is that part of common air that supports life, and without which neither light nor fire would burn, and hence this is called a supporter of combustion; such is chlorine, a yellow suffocating gas, which is the basis of bleaching liquids.

Although we cannot generally see gases, yet they are substantial; you cannot put water into a bottle unless the air is displaced; you cannot row a boat easily against the wind if a sail is up. They have weight also; some are very much heavier than others; the hydrogen put into balloons is of less weight than the mixture of oxygen and nitrogen called air, and it of course rises.

Mercury or quicksilver is an instance of a simple fluid body.

Metals are solids, except mercury. Most of the metals are dug out of the earth, mixed with other substances, and are called ores. It is the province of mining to dig out these ores, and to obtain the metal from them. Metals all expand by heat. There is a metal called platinum, which is very infusible; lead on the other hand is very fusible. Metals are the bases of lime, of soda, of potassa, But there are other simple solids not metallic, such as sulphur, charcoal or carbon, both which are in gunpowder. The diamond is pure carbon, the same as pure charcoal is. Phosphorus is a simple substance, luminous in the dark, and, when dry, will 'spontaneously inflame; in combination with lime this forms the basis of bones.

1. Vide Root. 2. All however will not unite, else we should have many thousand substances which do not now exist. Of the fifty-two simple elementary bodies, four are imponderable, as above stated, four are gaseous, six are nonmetallic and bases of acids, and thirty-eight are metallic, some of which are also bases of acids.