439 Chemical Essay.-Caloric. could it have arisen from any chemical action of the atmospheric air, since ice is not acted on by air or any of its principles. In other experiments, caloric was evolved when the friction was excited in vacuo. From these experiments, Mr. Davy inferred, that caloric must be derived from the motion and vibration of the particles of bodies, since he conceived it impossible to account for its production in any other way. The opinion which other chemists maintain, namely, that caloric is a material substance, is also supported by a number of facts; if, for example, caloric be applied to a body, whether solid, fluid, or aerial, the bulk of that body is very much enlarged: thus, when caloric is applied to water, it increases its volume 1800 times; and when it is applied to atmospheric air, or any gas, a very considerable expansion takes place: now upon the supposition that caloric is a mere vibratory motion, consisting of an alternate contraction and dilatation of the minute particles of bodies, it is impossible to account for the permanent increase of volume which takes place. Again, Pictet found that a thermometer introduced into the exhausted receiver of an air-pump, indicated both an increase and decrease of temperature; and Count Rumford shewed, that this takes place when the thermometer is introduced into the Torricellian vacuum. On immersing the apparatus with the thermometer into a quantity of warm water, an increase of temperature was indicated; when introduced into cold water, the temperature was decreased: these experiments are very much relied on by the advocates of the materiality of caloric; for in these cases there is no medium by which the vibratory motion can be produced. The radiation of caloric is regarded as another proof of its materiality. Something is thrown out in straight lines from heated bodies, which can be reflected and condensed; and which falling upon other bodies, increases their temperature: now it is difficult to conceive of a vibratory motion obeying these laws, and producing these effects. Lastly, the rays of the sun, which are proved to contain caloric, apart from the rays of light, are in favour of the opinion, that caloric is a material substance. The only diffi 440 culty which remains, therefore, in establishing this opinion is, to account for the fact of caloric being produced by friction and percussion. Independent of the conclusions which have been drawn by those who consider caloric to be a vibratory motion of the particles of bodies; those who have adopted the opposite opinion have come to different conclusions, by explaining, in a different manner, the experiments of their opponents: thus, for instance, they regard the caloric arising from percussion, as an effect of the condensation of the particles of that body which is submitted to percussion: the particles, they maintain, are forced into a more intimate union; and the caloric which they contain is evolved. Dr. Murray says, "It is far from being improbable, that the part of the body submitted to friction, and giving out the caloric in consequence of it, may receive caloric from the rest of the mass; owing to the elasticity of that agent, or its tendency to exist every where in a state of equilibrium. In the separation of the particles, caloric may flow from every side; the layer of matter immediately in contact with the surface, in a state of friction, may afford a quantity, which may be supplied from the matter contiguous to it; and thus a constant evolution may be kept up. Nor is it impossible, but that this may extend to a considerable distance from the surface to which the friction is applied; and even thro' different kinds of matter, if they are in contact." He conceives, that there is an analogy in these cases between caloric and electricity, as it regards their production, tending to establish his position. By friction, electricity is excited and forced out, while a new portion is received from the matter in contact with the electric substance, and ultimately from the earth itself. By this means a constant evolution is kept up. In the same manner, he contends that caloric may follow the same laws. There certainly appears to be an analogy in this instance; still, however, it may be very much doubted whether this can explain, in a satisfactory manner, the evolution and supply of caloric, which take place upon percussion. It is difficult to conceive in what way caloric is accumulated in such a large quantity, when 441 Poetry-Ode to the Genius of Collins. 442 a piece of iron is beat by a hammer | periments, with a view to determine for a length of time. whether caloric is subject to gravitation. The result of their experiments has been, that caloric produces no augmentation of weight in those bodies in which it is accumulated; on the contrary, some of their experiments seemed to indicate a diminution rather than an increase. We may suppose, however, that caloric, although it may be material, is such a subtile fluid, that its gravity cannot be ascertained by experiment. Its existence in a radiant state, in the solar beam, seems to be the only conclusive argument in favour of its materiality. A decided opinion, however, cannot be given; the presumption, perhaps, is in favour of its actual existence. (To be continued.) Berthollet has shewn, by some experiments, that the caloric which is produced by percussion, is entirely owing to the reduction of volume, or condensation, which takes place. He subjected different metals, gold, silver, copper, and iron, of the same size, to the stroke of the press, by which the impression is made on coin, and ascertained the heat produced, by throwing the piece of metal into water, immediately after the percussion, having previously ascertained by experiment the relation existing between a certain temperature produced in the water, and the temperature of the metal plunged into it, so as to draw the conclusion to what temperature it was raised by percussion. At the first stroke, the greatest degree of heat was produced; at the second, less heat was evolved; and at the third, still less. Berthollet farther discovered, that condensation takes place, when bodies are subjected to percussion, and this he was convinced of from the difference of specific gravity which occurs after bodies have been struck: the specific gravity of copper before it was struck was 8.8529, after the first stroke it was 8.8898, and after the second 8.9081: that of silver previous to percussion, was 10.4667; after being struck it was 10.4838. The different metals, too, gave more heat, as they suffered a greater condensation, copper having its temperature more raised than silver or gold, and its density being more increased by the operation. From these experiments, therefore, it is presumed that heat arises from condensation. Some have attempted to discover whether caloric is material, by ascertaining whether there is any difference in the weight of those bodies which have been exposed to it. Buffon, and others, made experiments of this natare; and although the results were favourable to the opinion that caloric is material, inasmuch as bodies exposed to heat indicated an increase of their absolute weight; still it was observed, that the sources of fallacy were numerous, and that the trifling increase of gravity might be ascribed to other circumstances. Dr. Fordyce, Count Rumford, and other chemists, have made several exNo. 27.-VOL. III. Poetry. ODE TO THE GENIUS OF COLLINS. HARK! I hear my breathing lyre, O shaded bard, and art thou near, Beyond the faint and shadowy forms Above this mortal bound of calms and storms, 443 Poetry-Stanzas.---The Last Day." The garb that veil'd their charms before! And from the deep secluded shrine WOOS In shepherd guise; the ruthless Tartar band; What angel spirit wakes thee now, As well might suit the chambers of the grave. Now comes a louder strain, -In sounds of mild and varied flow; Mid the pale mansions of the dead, Or dress the sod where Freedom fell? 444 Whilst flowers of Amaranth round thee blow? Thy heaven-born strains to fancy dear? STANZAS GEORGE TO THE MEMORY OF BENJAMIN WEST, ESQ. THO' awful is the closing scene When Wisdom, Worth, and Virtue die, Our bosoms feel the bitter pang, And sorrow prompts th' incessant sigh. Yet blessed is the closing scene, Th' immortal part from dross relin'd When resignation marks the hour; To blissful realms beyond the sky. This is the good man's closing scene, And this, much honour'd WEST, was thine! Swift as the winds, Fear struck the chords of My humble Muse in gratitude, woe, And onward fled. Hark, the dirges of the dead! And struck with mingled horrors strange Dropt his uplifted hand, and quench'd his deadly ire. Unrivall'd Bard! O Nature's son, Records his name for whom I mourn. To distant ages handed down; But we who knew thy private worth,- The blameless tenor of thy life, By us thou art sincerely mourn'd. THE LAST DAY. Tempus erit quo cuncta silent.—OVID. HARK! the tremendous trumpet shakes the skies: Louder, and still more dreadful, is its sound! Down from th' etherial realms of bliss, and roll And strike with dire dismay. The heart of man, Affrighted flies for refuge to the rocks, 445 Poetry-Egyptian Lotos.-The Cuckoo. Planets, and stars, and comets too, are hurl'd O'er the bewilder'd scene: Nor does the moon "That the imperial Judge of all mankind, To judge the silent dead." The yawning earth See! the great throne of Majesty appears, Each anxious eye is fix'd upon the Judge, There the tormented miserable throng, Of the dark, dreary, endless fire of hell Lostwithiel, Oct. 24, 1820. THE EGYPTIAN LOTOS. R. L. 446 When at their noontide height, his fervid rays To brave the Tropic's fiery beam is thine, What mystic treasures in thy form conceal'd, eye. From thy prolific vase and fertile seeds And lovelier germs shoot forth, and brighter Thus, from Arabia borne, on golden wing, Nor food to th' enlighten'd mind alone, But far beyond the bounds of Afric borne, Thy Pharaohs moulder in their marble tombs; Still 'mid these ruin'd towns, admir'd, rever'd, rear'd, fade, With being's self thy beauteous tribe decline; TO THE CUCKOO, ON HEARING IT FOR THE FIRST TIME. AH! welcome Messenger of Spring, *447 NININ A Fragment.---On the Atonement. The peasant and the village swain, And hear thee hail the blest return of Spring, A double welcome, happy bird- Thy notes, that with them bring such joy. Why is it that thou wilt not stay Yes, bird of pleasure, thou dost seize Had I thy wings, I too would fly, 66, Queen-street, Cheapside, London. * The Cuckoo is rarely heard after June. A FRAGMENT. WHEN lost in thought my soul doth soar That hymns the concert of the sky. No superstition there doth dwell, Their instruments, we cannot know, But, hark! where can those notes be found? Hark now the sounds more strongly rise, The sweet-ton'd trio now declines, On the Atonement. MR. EDITOR. 448 J. N. SIR, In the Imperial Magazine for March 1821, you profess it was your intention to publish that month an article you had received on the Atonement, had not your premises been destroyed by fire. And engaging it shall speedily appear, if another copy be sent you; and presuming that the allusion is to a little production of my pen, on that momentous subject, I now again send you my thoughts, as I think many of my brethren form erroneous views of this most important doctrine, when applied to the character our Lord delïneates, Mark xii. 30, 31. Ephesians iii. 17, 18, 19.; 1 Thess. v. 23. 1 John iii. 3, 6. and John iv. 13, 16. The word atone, has two meanings given to it by the religious world; and strange as it may appear, those meanings seem to be in direct opposition to each other. The only sense in which the Scriptures use it, in its application to the above character, appears to be the following; At-One'; Union, Concord, Harmony, Agreement, involving in it the idea of two parties, formerly at variance, being now perfectly reconciled through some intervening medium, Rom. v. 11. And the idea attaching to this term, implies that a propitiatory offering has been made, whereby this reconciliation is effected; and that when this end is accomplished, the cause which induced the former separation is altogether annihilated; and the two par ties are as completely one, not only as though no enmity had ever subsisted between them, but as though they now formed one constituent indissoluble body. Agreeable to this, are our Saviour's declarations:-" As thou, Father, art in me, and I in thee, that they also may be one in us.—I in them, and |