and tells me that my earthly affections are opposing my heavenly desires and consolations,

INSECTS.-No. XXXVII.

(Hearing.)

BEFORE proceeding immediately to the prescribed topic of this paper, may be well to remark, that men of science are scarcely yet agreed as to the senses of insects, and that the use of some of their organs, which appear to be organs of sensation, has not yet been satisfactorily ascertained. As to the senses in general, it need scarcely be stated that touch, taste, smell, hearing, and sight, is the ordinary enumeration of them; but as the term includes every means of communication with the external world, the list might, perhaps, be increased. Kirby contends, for instance, for an internal sense. He says, "The picture may be painted upon the retina of the eye, and the sound may strike on the tympanum of the ear; but neither the one nor the other be received by the intellect, unless the internal power or faculty of perception be in action, and mediate between them. This is what I mean by the internal sense, which, to use a term of Mr. W. S. MacLeay's, is osculant between intellect and sense, or forms the transit from one group of powers to the other."

In man the ordinary five senses are usually in their greatest perfection, although in some animals particular senses have a greater range. The vertebrates in general are also gifted with the same number, though there are some exceptions. But in the invertebrates they are seldom to be met with altogether in the same object. Some creatures have no smell; several can neither hear nor see. The animals of bivalve shells have neither eyes, nor ears, nor smell; and the zoophytes, and the races below them, have, it is affirmed, only the single sense of touch, which in them is so extremely delicate as to be acted upon even by light. Not so are insects. These, there good reason to believe, possess all the ordinary senses. Linne and Bonnet, however, thought them deprived of hearing; but numerous observations prove the contrary. That they hear in their larva state, is evident from facts stated by the latter. He found that the sound of his voice evidently affected some ca terpillars; which he attributes, but surely without reason, to the delicacy of their

sense of touch; at another time, when some caterpillars of a different species were moving swiftly, he rang a small bell, on which they instantly stopped, and moved the anterior part of their body very briskly. That they possess this power in their imago state, is confirmed still more strongly by facts. "I once was observing," says Kirby, "the motions of an apion, under a pocket microscope. On seeing me, it receded: upon my making a slight but distant noise, its antennæ started. I repeated the noise several times, and invariably with the same effect. A harpalus, which I was holding in my hand, answered the sound in the same manner, repeatedly. Flies, I have observed, at brisk and distinct sounds, move all ten legs and spiders will quit their prey, and retire to their hiding places." Insects that live in society give notice of intended movements, or assemble their citizens for emigration, by a certain hum. This occurs in the evening, and is continued even during the night; all seems to be in a bustle, the greatest restlessness agitates the bees. Sometimes to hear this hum the ear must be placed close to the hive, when clear and sharp sounds may be distinguished, which appear to be produced by the vibration of the wings of a single bee. This hum has been gravely construed by some into an harangue of the queen to animate her subjects to the great undertaking which she now meditates the founding of a new empire. "There sometimes seem to happen suddenly amongst them," says Reaumur, " events which put all the bees in motion, for which no account can be given. you observe a hive with attention, you may often remain a long time and hear only a slight murmur, and then, all in a moment, a sonorous hum will be excited, and the workers, as if seized by a panic terror, may be seen running off in different directions. At these moments, if a young queen goes out, she will be followed by a numerous troop.

If

The various sounds produced by insects suggest that they must have the power of hearing. "Our male green field-hoppers,' says De Geer, "in that part of the right wing-case which is folded horizontally over the trunk, have a round plate made of a very fine transparent membrane, resembling a little mirror, or piece of talc, and as tense as a drum. It is surrounded by a strong and prominent nervure, but is concealed under the fold of the left wing-case, where there are also strong nervures corresponding with what may be called the hoop of the

drum. It is exceedingly probable that the quick motion with which the insect rubs these nervures against each other, produces a vibration in the membrane, whence the sound is augmented." By alternating the motion rapidly from right to left, the sound is produced in an almost continued strain. But the power of hearing in these creatures is placed beyond all doubt. Brunelli, an Italian naturalist, kept and fed several males of a grasshopper, not uncommon with us, in a closet, which were very merry, and continued singing all the day; but a rap at the door would stop them instantly. By practice he learned to imitate their chirping: when he did this at the door, at first a few would answer him in a low note, and then the whole party would take up the tune and sing with all their might. He once shut up a male in his garden, and gave the female her liberty; but as soon as she heard the male chirp, she flew to him immediately.

The grasshoppers and locusts produce their chirp by applying the hind shank to the thigh, rubbing it smartly against the wing-case, and alternating the right and left legs. They have also a drum, like the preceding family, for augmenting the sound. "On each side," says De Geer, "of the first segment of the abdomen, immediately above the origin of the hind thighs, there is a large deep opening, somewhat oval in form, and partly closed by an irregular flat plate or lid, of a hard substance, but covered by a flexible, wrinkled membrane. The opening left by the lid is in form of a half-moon, and at the bottom of the cavity is a white membrane, shining like a mirror, and tensely stretched. On the side of the opening, towards the head, there is a small oval hole, into which the point of a pin may easily pass; and when the membrane is removed, a large cavity is brought into view. The whole of this apparatus seems to contribute much both to produce and to increase the sound caused by insects."

SCRIPTURE EXPLANATIONS. No. XXIV. THE SEVEN CHURCHES OF ASIA.

Their History and present State. EPHESUS, in the time of the Romans, was the metropolis of proconsular Asia, This celebrated city, the vast remains of which give a high idea of its former beauty, extent, and magnificence, was situated in that part of Asia which was anciently called Ionia, (but now Natolia,) about five miles from the Ægean sea, on the sides and at

the foot of a range of mountains overlooking a fine plain that was watered and fertilized by the river Cayster. Ephesus was particularly celebrated for the temple of Diana, a most magnificent and stately edifice, which had been erected at the common expense of the inhabitants of Asia Proper, and was reputed one of the seven wonders of the world: but the very site of this magnificent and celebrated edifice is now undetermined, though some stupendous columns in the large mosque, there is reason to believe, once graced that structure. Widely scattered and noble ruins attest the splendour of the theatre mentioned in Acts xix. 31; the elevated situation of which, on Mount Prion, accounts for the ease with which an immense multitude was collected; the loud shouts of whose voices, reverberated from the neighbouring mount Corissus, would not a little augment the uproar which was occasioned by the populace rushing into the theatre, just below which is the public place where the law proceedings were going forward, to which the town-clerk referred Demetrius and his companions. In the time of Saint Paul, this city abounded with orators and philosophers; and its inhabitants, in their gentile state, were celebrated for their idolatry and skill in magic, as well as for their luxury and licentiousness.

The present state of Ephesus affords a striking illustration of the accomplishment of prophecy. Ephesus is the first of the apocalyptic churches addressed by the evangelist in the name of our Lord Jesus Christ. "His charge against her is a declension in religious fervour, Rev. ii. 4; and his threat in consequence, (verse 5,) a total extinction of her ecclesiastical brightness. After a protracted struggle with the sword of Rome, and the sophisms of the gnostics, Ephesus at last gave way. The incipient indifference, censured by the warning voice of the prophet, increased to a total forgetfulness; till at length the threatenings of the Apocalypse were fulfilled, and Ephesus sunk with the general overthrow of the Greek empire in the four teenth century."

Ephesus is now under the dominion of the Turks, and is in a state of almost total ruin; innumerable inscriptions are lying about in disorder or neglect, or built into the Turkish structures. The plough has passed over the city; and in March 1826, green corn was growing, in all directions, amidst the forsaken ruins; and one solitary Greek only was found, who bore the name of Christ, instead of its once flourishing

ruins.

SMYRNA, a city of Asia Minor, was situated about forty miles to the north of Ephesus, of which city it was originally a colony. It is now celebrated chiefly for the number, wealth, and commerce of the inhabitants. Of its population, which is estimated at about 75,000 inhabitants, 45,000 are Turks; 15,000 Greeks; 8000 Armenians; 8,000 Jews; and less than 1,000 Europeans. There are more than twenty mosques in Smyrna, and three Greek churches, and the Jews have several synagogues. The angel of the church of Smyrna, addressed in the second apocalyptic epistle, is supposed to have been Polycarp, the disciple of Saint John, by whom he was appointed bishop of Smyrna. As he afterwards suffered much, being burnt alive at Smyrna, A. D. 166, the exhortation in Rev. ii. 10 would be peculiarly calculated to support and encourage him. Smyrna will ever interest the real christian. On the firmness of the early martyrs depended, under Divine Providence, the transmission of the truth to the latest generations.

66

PERGAMOS was the ancient metropolis of Mysia, and the residence of the Attalian kings; it still preserves many vestiges of its ancient magnificence. Against the church at Pergamos, was adduced the charge of instability, Rev. ii. 14, 15, but to its wavering faith was promised the all-powerful protection of God. "The errors of Balaam and the Nicolaitanes have been purged away. Pergamos has been preserved from the destroyer; and three thousand christians" (out of a population of about 15,000 inhabitants) now cherish the rites of their religion in the same spot where it was planted by the hands of Saint Paul, though, alas! their religion has little in common with the faith taught by the apostle, but the name and profession. Of these christians, about 200 belong to the Armenian communion; the remainder are members of the Greek church. They have each one church, but the other churches of Pergamos have been converted into mosques, and are profaned with the blasphemies of the pseudoprophet, Mohammed. There are also about

THYATIRA, a city of Asia Minor, was a considerable city in the road from Pergamos to Sardis, and about forty-eight miles eastward of the former. It is called by the Turks, Akhisar, and is embosomed in cypresses and poplars; it is now, as anciently it was, celebrated for dyeing, and large quantities of cloths, dyed scarlet, are sent weekly to Smyrna. In 1826, the population was estimated at 300 Greek houses, thirty Armenian, and 1000 Turkish. Each of the two former have a church. The streets are narrow and dirty.

SARDIS, the metropolis of the region of Lydia, in Asia Minor, is situated near mount Tmolus, between thirty and forty miles east from Smyrna. It was celebrated for great opulence, and for the voluptuous and debauched manners of its inhabitants. Considerable ruins still attest the ancient splendour of this once celebrated capital of Croesus and the Lydian kings, which is now reduced to a wretched village, called Sart, consisting of a few mud huts occupied by Turkish herdsmen. "A great portion of the ground once occupied by this imperial city, is now a smooth grassy plain, browsed over by the sheep of the peasants, or trodden by the camels of the caravan; and all that remains to point out the site of its glory, is a few disjointed pillars, and the crumbling rock of the Acropolis." The ruins are more entirely gone to decay than in most of the ancient cities in those parts. No christians reside on the spot; two Greek servants of a Turkish miller, in 1826, were the only representatives of the church at Sardis; the present state of which affords a most striking illustration of the accomplishment of the prophetic denunciation against the church in that city-A name to live, while dead.

(To be continued.)

SIMPLE MACHINES-THE LEVER. (Continued from page 133.) THE balance, as we have already stated, is a lever of the first order, with equal arms, and its use is to determine unknown weights. The balance, as made by the best workmen, consists of a light beam of some inflexible material, but its shape differs according to the caprice or skill of

the constructor. Ramsden's celebrated balance-beam consisted of two cones, joined at their bases, and to the centre of the beam is attached a finely polished knifeedge, which works upon polished agates; but that these delicate edges may not be injured by reclining for any length of time on the agate planes, supporting the whole weight of the balance, two upright forks are provided, which may be elevated by touching a small attached lever or screw, which causes them to seize the beam, and hold it suspended. A good instrument for philosophical purposes should indicate to 1-30,000th part of the weight in the scale. In all well-constructed beams the centre of gravity is immediately under the centre of motion, that is the axis; for if it be above the axis, the slightest motion will cause it to upset, being in a state of instable equilibrium; and if the centre of motion be also the centre of gravity, then the arms will rest indifferently in any position.

The general theory of weighing is, to place the substance whose weight is required in one scale, and to add weights to the opposite scale until the balance beam is in equilibrio. But in weighing bodies that have but little weight, there are many circumstances to be attended to, or the weight cannot be accurately estimated. The weights themselves must not be touched with the fingers, for the heat that would be communicated, might be sufficient to cause light currents of air that would derange the balance, even if no impurity were communicated. These currents of air must be carefully guarded against, and it is therefore desirable to remove the weights by means of a small pair of nippers. It was once asserted that the principle called caloric, or heat, had weight, because a flask of water weighs more when the liquid is cold, than when it is hot; but this does not arise from any influence that caloric has upon weight, but because a current of air is produced when the temperature is raised, which ceases when the water is cold. It is often advantageous in delicate chemical experiments, requiring the art of weighing, to be able to construct your own small weights; and this may at any time be done. Take a length of silver or platinum wire, the latter is preferable, weighing, for instance, one grain. By carefully measuring the length, it is easy to determine the proportionate lengths required to produce any given weight less than a grain. Supposing that a weight one-hundredth of

a grain be required, measure a piece of wire weighing exactly one grain, and onehundredth part of the whole length will give the weight required: in this way the student may construct the smallest possible weights by using wires of proportional thinness.

Another modification of the lever used to determine the weight of bodies, is the Roman balance, or common steelyard, which is, strictly speaking, a lever of the first order. It consists of an iron beam moving on a pivot, having one arm much longer than the other. These two arms are so balanced that the beam is horizontal when unloaded. A hook is fixed to the shorter arm, on which the substance to be weighed is suspended. On the longer arm a determined weight is placed, which slides into any position, and the equilibrium of the lever or weight of the body is obtained, by bringing the weight nearer to, or further from, the centre of motion. The longer arm being graduated, the point at which the weight remains will give the weight of the body. This instrument is well known, being commonly used in families, and in some trades. Its principle of action is the same as the lever, that is to say, the weight multiplied into its distance from the fulcrum, is equal to the power multiplied into its distance.

There are many other modifications of the lever adapted to weighing, as the Danish balance, Brady's balance, and others, to which we cannot at present refer; all these, however, act upon the same principle, and the reader may easily acquaint himself fully with the action of this beautiful though simple machine, by taking all the opportunities which present themselves of applying the law we have explained.

USEFULNESS OF METALS.

If a convincing and familiar proof of the extensive application of the metals to the common purposes of life were required, we need only refer to the case of many a common cottager, who could not carry on his daily concerns and occupations without the assistance of several of the metals. He could not, for instance, make his larger purchases, nor pay his rent, without silver, gold, and copper. Without iron, he could neither dig, nor plough, nor reap; and, with respect to his habitation, there is scarcely a part of the structure itself, or of the furniture contained in it, which is not held together, to a greater or less extent, by means