two thousand, we must look for the de liverance of Israel.

About two thousand years before the birth of Christ, Abraham, a descendant of Shem, was born. Jehovah called this individual, saying, "Get thee out of thy country, and from thy kindred, and from thy father's house, unto a land that I will shew thee. And I will make of thee a great nation, and I will bless them that bless thee, and make thy name great; and thou shalt be a blessing. And I will bless them that bless thee, and curse him that curseth thee; and in thee shall all families of the earth be blessed. So Abram departed, as the Lord had spoken unto him; and he believed in the Lord; and He counted it to him for righteousness; and he was called the friend of God." Thus was the standard of truth erected amidst the heathen, that all the earth might know and fear Jehovah.

About fifteen hundred and seventy years before the birth of Christ, Moses, a descendant of Abraham, was born in Egypt, during a severe bondage, under which the descendants of that great man had become very numerous, and had fallen in that country; and at the command, and by the power of Jehovah, Moses became the instrument of their deliverance therefrom. Having beheld the wonders wrought by Jehovah in Egypt, and in their passage through the Red Sea, on arriving at Mount Sinai, this whole nation were set apart to God, as a beacon to the world, and there, entering into covenant with God, they received laws from heaven. Here they erected a magnificent tabernacle for the ordained service of Jehovah, where, over the mercy-seat, between the cherubim, upon the ark of the covenant, within the most holy place, the Divine presence abode perpetually; becoming the Judge and the Oracle of Israel, feeding His people with bread from heaven, and giving them power over their enemies.

Rebellion succeeded rebellion in the wilderness, where they wandered forty years, until the whole of the men of war, except two persons, Caleb and Joshua, perished beneath the just judgments of God. But mercy was extended to their children, and they entered, through the waters of Jordan, which were miraculously divided, dry-shod into the land of Canaan; the nations of which fell before them, and therein they had rest. The tabernacle of Jehovah was pitched in Shiloh, in the land of Canaan; and thither the sons of Abraham resorted to worship God. But the glory of the taber. nacle passed away, to rise no more, on the

defection of both priests and people from God, under Eli, when, in one day, he died, his sons were slain, and the ark of the covenant was taken by the armies of the Philistines, about the year eleven hundred and forty before Christ, 1 Sam. iv. Psa. lxxviii. Jer. vii.

The most magnificent temple which the world ever witnessed, succeeded the taber. nacle, when the state of Israel was in the zenith of its splendour, under Solomon, the son of David, about the year one thousand before Christ. Into this temple, which was erected at Jerusalem, the ark of the covenant, with all the sacred utensils of the tabernacle, were introduced, and therein, over the mercy-seat, abode the Divine presence, re-become the judge and the oracle of Israel, and confirming to that people all the former covenants.

An awful division of the tribes of Israel took place on the death of Solomon, when two tribes, Judah and Benjamin, only remained faithful to the house of David; while the other ten elected a king for themselves, commenced idolatrous worship, and rebelled against the Judge of Israel. About the year seven hundred and twenty before Christ, the judgments of Jehovah came upon these ten tribes, for all their wickedness; and the king of Assyria took all the cities of Israel, slaughtered their armies, destroyed the state, and carried away captive the remnant of that people into distant countries, from whence they have never returned to Canaan; nor of these have we any authentic account in history, even to this day.

About the year five hundred and ninety before Christ, the glory of the temple, and with it Jerusalem, all Judea, and the two tribes which adhered to the house of David, after many pollutions, finally fell before the armies of Nebuchadnezzar, king of Babylon, who burnt the city and the temple, put down the state, and carried away captive the remnant of the people to Babylon: "By the rivers of Babylon, there we sat down; yea, we wept, when we remembered Zion," exclaimed the psalmist on this mournful occasion; and after many years, Daniel, the holy prophet, with fasting, sackcloth and ashes, cried unto the Lord our God, Hear the prayer of thy servant, and his supplications, and cause thy face to shine upon thy sanctuary that is desolate, for the Lord's sake. O Lord, hear; O Lord, forgive; O Lord, hearken and do; defer not, for thine own sake, O my God: for thy city and thy people are called by thy name."

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The Lord heard the prayer of his pro

phet; and about the year before Christ five hundred and thirty-six, seventy years from the first sacking of Jerusalem and the temple, when Nebuchadnezzar carried off the king, and the vessels of the house of the Lord, to Babylon, 2 Chron. xxxvi., Cyrus issued that famous decree, Ezra i., under which the captives of Judah and Benjamin returned to Canaan, and built the second temple-"The house of the Lord God of Israel (he is the God) in Jerusalem." Of this temple, the prophet Haggai, who flourished under Zerubbabel, the governor, and Josedech, the high priest, during its erection, prophesied, "The Desire of all nations shall come and I will fill this house with glory, saith the Lord of hosts. The glory of this latter house shall be greater than of the former, saith the Lord of hosts and in this place will I give peace, saith the Lord of hosts."

The sceptre was about to depart from Judah, and the lawgiver from between his feet, and pass to the Romans, when Shiloh came, in the fulness of time; and unto him is the gathering of the people, Genesis xlix. Previous to this period, the temple built under the decree of Cyrus, after passing through hosts of spoliations and profanations, (of which that under Antiochus was the most awful,) amidst the inflictions of those turbulent times, was repaired, beautified and enriched up to the most splendid edifice then in the world; and it was in the zenith of its grandeurs that Shiloh came thereto, and therein first set up that kingdom of heaven-of peace and joy in the Holy Ghost, which characterize the saints of the Most High. Thus was the prophecy of Jehovah-Isebaoth, by the mouth of Haggai, fulfilled, viz., "The glory of this latter house shall be greater than of the former; and in this place will I give peace."

Moses was inspired, when he delivered the law of Jehovah to Israel, to declare unto that people, "The Lord thy God will raise up unto thee a prophet from the midst of thee, of thy brethren, like unto me; unto him ye shall hearken. And it shall come to pass, that whosoever will not hearken unto my words, which he shall speak in my name, I will require it of him," Gen. xviii. Jesus, the Christ, the Son of God, was the seed of Abraham, the Shiloh of Jacob, the prophet like unto Moses, the seed of the woman, the son of David the shepherd, the king of Israel, the Redeemer of mankind, the Saviour of the world. He came to his own, but his own received him not. Instead of receiving his glorious gospel, the elders, the

priests, and the people of Israel, cast him out of the temple, condemned him to die, clamoured for his crucifixion to Pilate, drove him out of Jerusalem, after scourging, buffeting, and crowning him with thorns, and on Calvary crucified him between two thieves. Yea, instead of hearkening to this prophet, the Son of God, who knew no sin, they said among themselves, "This is the heir; come, let us kill him, and let us seize on his inheritance. And they caught him, and cast him out of the vineyard, and slew him. And the Lord came, and miserably destroyed these wicked men. For the Roman armies came, slew innumerable multitudes of the Jews, besieged, took, and destroyed Jerusalem, burnt the temple, annihilated the state, and sold the remnant of that nation for slaves; dispersing them into all nations, about seventy years after the birth of Christ, the Son of God.

Thus were the husbandmen, unto whom Jehovah originally intrusted his vineyard, slain, because of their wickedness; and the Lord's vineyard was given to others, viz. the Gentiles; and this is the destruction of the land of Canaan, the people, and Jerusalem, noted in the prophecy of Christ, Luke xxi. Which destruction and dispersion of the remnant of the descendants of Abraham, continue even to this day. The Mosaic sanctuary is now no more; the bodies of the saints are the temples of the Holy Ghost; and wherever two or three are gathered together in his name, there the Lord is in the midst of them. Of this more hereafter. WM. COLDWELL. King Square, January 20, 1832.

SOME OBSERVATIONS ON THE NATURE OF LIGHT AND COLOURS.

Ir is stated, in the first five verses of the first chapter of Genesis, that “In the beginning God created the heavens and the earth, and the earth was without form, and void; and darkness was upon the face of the deep. And God said, Let there be light; and there was light. And God divided the light from the darkness; and he called the light Day, and the darkness he called Night. And the evening and the morning were the first day."

In the fourteenth and five following verses of the same chapter, it is said, "God made two great lights to rule the day and the night, and set them in the firmament of the heaven, to give light upon the earth,

and divide the light from the darkness; and the evening and the morning were the fourth day."

It would seem from the preceding verses, that Moses, or whoever was the author of the book of Genesis, was aware of a fact, the discovery of which, is in general supposed to be due to philosophers of the present day; i. e. that light is a real material substance, existing per se, and transmitted to us through the medium, or by the action, of certain bodies termed luminous. On the first day, God created the light, but it was not reflected upon the earth, through the various media of the sun, moon, and stars, till the fourth day, when a necessity had arisen for it, on account of the earth having brought "forth grass, the herb yielding seed, and the fruit-tree yielding fruit."

The nature of light has been a subject of speculation from the earliest ages of philosophy. Some of the most ancient sages doubted whether objects became visible by a kind of emanation proceeding from them, or from the eye of the spectator. The fallacy of this opinion must soon have become apparent, because, in that case, men ought to see as well in the night as in the day; and, it is evident that something more than the mere presence of an object is necessary to render it visible: it is astonishing that such men as Empedocles, Plato, and Pythagoras could have disputed upon such a subject. All objects, to be visible, must be in a certain state, that is, either self-luminous, as the sun, moon, stars, red-hot metal, &c., or, in the presence of a self-luminous body, so that the substance called light may form a communication between the eye and the objects viewed.

Among moderns, there are two principal opinions-the Newtonian, so called from its illustrious inventor; and the Undulatory, supported by Huygens, Euler the mathematician, and others equally celebrated. A third has been brought forward by Professor Oersted, who considers light to be produced by a succession of electric sparks, or a series of decompositions and recompositions of an electric fluid, filling all space in a natural or balanced state; this last opinion has met with few advocates.

The following are the postulata assumed in the Newtonian or Corpuscular theory.

1. That light consists of particles of matter possessed of inertia, and endowed with attractive and repulsive forces, and projected or emitted from all luminous bodies with nearly the same velocity, i. e. about 200,000 miles per second.

2. That these particles differ from each

other in the intensity of the attractive and repulsive forces which reside in them, and in their relations to the other bodies of the material world, and also in their actual masses, or inertia.

3. That these particles, impinging on the retina, stimulate it, and excite vision: the particles whose inertia is greatest, producing the sensation of red; those of least inertia of violet; and those in which it is intermediate, the intermediate colours.

4. That the molecules of material bodies, and those of light, exert a mutual action on each other, which consists in attraction and repulsion, according to some law or function of the distance between them; that this law is such, as to admit, perhaps, of several alternations, or changes from repulsive to attractive force; but that, when the distance is below a certain very small limit, it is always attractive up to actual contact; and that, beyond this limit, resides, at least, one sphere of repulsion. This repulsive force is that which causes the reflexion of light at the external surfaces of dense media; and the interior attraction, that which produces the refraction and interior reflexion of light.

5. That these forces have different absolute values, or intensities, not only for all different material bodies, but for every different species of the luminous molecules, being of a nature analogous to chemical affinities, or electric attractions, and that hence arises the different refrangibility of the rays of light.

6. That the motion of a particle of light, under the influence of these forces, and its own velocity, is regulated by the same mechanical laws which govern the motions of ordinary matter, and that, therefore, each particle describes a trajectory capable of strict calculation, so soon as the forces which act on it are assigned.

7. That the distance between the molecules of material bodies is exceedingly small, in comparison with the extent of their spheres of attraction and repulsion on the particles of light. And,

8. That the forces which produce the reflexion and refraction of light are, nevertheless, absolutely insensible at all measurable or appreciable distances from the molecules which exert them.

9. That every luminous molecule, during the whole of its progress through space, continually passing through certain periodically recurring states, called by Newton, fits of easy reflexion and easy transmission, in virtue of which (from whatever cause arising, whether from a rotation of the molecules on their axes, and the consequent

alternate présentation of attractive and repulsive poles, or from any other conceivable cause) they are more disposed, when in the former states or phases of their periods, to obey the influence of the repulsive or reflective forces of the molecules of a medium; and, when in the latter, of the attractive.

It is evident, from the foregoing postulata, that in the Newtonian theory, a ray of light is understood to mean a continued succession or stream of molecules, all moving with the same velocity along one right line, and following each other close enough to keep the retina in a constant state of stimulus, i. e. so fast, that before the impression produced by one can have time to subside, another shall arrive. It appears, by experiment, that, to produce a continued sensation of light, it is sufficient to repeat a momentary flash about eight or ten times in a second. For example, if the point of a stick be heated to redness, and it be then whirled round in a circle, with a greater velocity than eight or ten circumferences per second, the eye can no longer distinguish the place of the luminous point at any instant, and the whole circle appears equally bright and entire. This shews, evidently, that the sensation excited by the light falling on any one point of the retina, must remain almost without diminution till the impression is repeated, during the subsequent revolution of the luminous body.

Now, if uninterrupted vision can be produced by momentary impressions, repeated at intervals so distant as the tenth of a second, it is easy to conceive that the individual molecules of light in a ray, will not require to follow close on each other, to affect our organs with a continued sense of light. For, as the velocity of particles of light has been ascertained to be nearly 200,000 miles per second, if they follow each other at intervals of 1000 miles apart,

200 of them would still reach our retina per second in every ray. This consideration removes all difficulties on the score of their jostling, or disturbing each other in space, and allows of infinite rays crossing at once through the same point of space, without at all interfering with each other, especially when we consider the minuteness which must be attributed to them, that, moving with such swiftness, they should not injure our visual organs. If a molecule of light weighed but a single grain, its inertia would equal that of a cannon-ball upwards of 150 pounds weight, moving at a rate of 1000 feet per second. What, then, must be their tenuity, when the concentration of millions upon millions of them, by lenses

or mirrors, has never been found to produce the slightest mechanical effect on the most delicately-contrived instruments, during experiments made expressly to detect it.

The Undulatory theory, whose chief supporters are Huygens, Descartes, Hooke, Euler, Young, and Fresnel, requires the admission of the following postulata:

1. That an excessively rare, subtle, and elastic medium, or ather, as it is called, fills all space, and pervades all material bodies, occupying the intervals between their molecules; either by passing freely among them, or, by its extreme rarity, of. fering no resistance to the motions of the earth, the planets, or comets, in their orbits, appreciable by the most delicate astronomical observations; and having inertia, but not gravity.

2. That the molecules of this æther are susceptible of being set in motion by the agitation of the particles of ponderable matter; and that when any one is thus set in motion, it communicates a similar motion to those adjacent to it; and thus the motion is propagated further and further in all directions, according to the same mechanical laws which regulate the propagation of undulations, in other elastic media, as air, water, or solids, according to their respective constitutions.

3. That in the interior of refracting media, the æther exists in a state of less elasticity, compared with its density, than in vacuo, i. e. in a space empty of all other matter; and that the more refractive the medium, the less, relatively speaking, is the elasticity of the ether in its interior.

4. That vibrations communicated to the æther in free space, are propagated through refractive media, by means of the æther in their interior, but with a velocity corresponding to its inferior degree of elasticity.

5. That when regular orbratory motions of a proper kind are propagated through the æther, and, passing through our eyes, reach and agitate the nerves of our retina, they produce in us the sensation of light, in a manner bearing a more or less close analogy to that in which the vibrations of the air affect our auditory nerves with that of sound.

6. That as, in the doctrine of sound, the frequency of the aerial pulses, or the number of excursions to and fro from its point of rest, made by each molecule of the air, determines the pitch, or note; so, in the theory of light, the frequencies of the pulses, or number of impulses made on our nerves in a given time by the ethereal molecules next in contact with them, determines the colour of the light; and that as the absolute

extent of the motion to and fro of the particles of air determine the loudness of the sound, so the amplitude, or extent, of the excursions of the aetherial molecules from their points of rest, determine the brightness or intensity of the light.

These last postulata necessarily are liable to considerable obscurities; as the doctrine of the propagation of motion through elastic media is one of the most abstruse and difficult branches of mathematical inquiry, and we are therefore perpetually driven to indirect and analogical reasoning, from the utter hopelessness of overcoming the mere mathematical difficulties inherent in the subject. The fact is, that neither the Newtonian, nor the Undulatory, nor any other system which has yet been devised, will furnish that complete and satisfactory explanation of all the phenomena of light which is desirable. Certain admissions must be made at every step, as to modes of mechanical action, where we are in total igno. rance of the acting forces; and we are called on, where reasoning fails, occasionally for an exercise of faith.

The two systems may be briefly summed up as follows:

According to the Undulatory theory, light is an invisible fluid, present at all times and in all places, but which requires to be set in motion by an ignited, or otherwise properly qualified body, in order to make objects visible to us. Huygens believed that the sun when it rose agitated this fluid, and that the undulations gradually extended themselves till they struck the eye of the spectator who then beheld the sun.

The Newtonians maintain, that light is not a fluid per se, but that it consists of a vast number of exceedingly small particles shaken off in all directions from the luminous body with inconceivable velocity, by a repulsive power; and which, most probably, never return again to the body from which they were emitted.

Light emanates, radiates, or is propagated from all luminous bodies in straight lines, and in all directions, but, perhaps, not equally in all directions. A succession of these particles is called a ray of light, and that this ray must proceed in a straight line is evident from the following facts.

If an opaque body be interposed between the sun and a sheet of white paper, or other object, it casts a shadow on such object; ie. renders it non-luminous. A ray of light will not pass through a bent metallic tube, or through three small holes in as many plates of metal, placed one behind the other at a distance, unless the holes be situated exactly in a straight line. Moreover, the 2D. SERIES, NO. 14.- VOL. II.

shadows of bodies, when fairly received on smooth surfaces perpendicular to the line in which the luminous body lies, are similar in figure to the section of the body which produces them, which could not be, except the light were communicated in straight lines from their edges to the borders of the shadow.

That light radiates from every point of a luminous body, may be proved by the following experiment. If a ray of the sun be admitted through a small round hole into a darkened room during a solar eclipse, and received on a white screen, the spot of light, instead of appearing round, will present the appearance of the body of the sun; i. e. it will be horned. Now, if a hole be made in the screen which receives the image of the sun, and the ray of light be permitted to pass through it to a second screen, the spot of light will no longer present the appearance of the body of the sun, but that of the hole made in the first screen. Again, take a sheet of pasteboard, and drill a small hole through it with a needle, put a white screen behind it, and let the light of a candle pass through the small hole to the screen; in this case we shall have not a small round point of light, but an exact image of the flame of the candle, inverted: if the light from two, four, or six candles, be suffered to pass through the same minute hole, we shall not have a brighter, or larger spot of light, but as many distinct flames as there are candles: thus proving that every physical point of a luminous surface is a separate and independent source of light.

Light requires time for its propagation, or takes time to travel over space. Two spectators at different distances from a luminous object suddenly disclosed, will not begin to see it at the same mathematical instant of time; the nearer will see it sooner than the more remote. In like manner, if a luminous object be suddenly extinguished, a spectator will continue to see it for a certain time afterwards, as if it still continued luminous, and this time will be longer the farther he is from it.

The interval in question is, however, so excessively small in such distances as occur on the earth's surface, as to be absolutely insensible; but in the immense expanse of the celestial regions the case is different. The eclipses and emersions of Jupiter's satellites become visible nearly a quarter of an hour sooner, when the earth is at its least distance from that planet, than when at its greatest. Recent observations have enabled astronomers to assign, with great precision, the numerical amount of this inequality, and thence to deduce the velocity of light, which 158.-VOL. XIV.

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