: served in their perfect forms. animals that lived in the sea. Some of them are the shells of As the Cypræa inflata or the Cowry, 20-the Fusus, 26-the Cerithium Lamellosum, 14the Pleurotoma, 17-the Lucina, 3-the Ampullaria, 22-the Venericardia, 7-the Mitra, 19-the Rostellaria, 23. In the Red Crag of Suffolk, a peculiar kind of Fusus, called Fusus contrarius, is found, having the whorl and the mouth in a contrary direction. Others are fresh-water shells; such as the Cyclostoma, 6-the Planorbis, 10-the Helyx, 12-the Cyrena cuneiformis, 1. the serpent. The crocodiles resemble those which now exist in Borneo. The tortoises are both marine and fresh-water, but the marine ones are fewer in number than the others, and they are smaller in size than those now existing. The serpents are of the tribe now represented by the Boa Constrictor and the Python, such as are now found only in tropical climates, and feeding on birds and quadrupeds. Some of them were of large dimensions and measuring in length from ten to twenty feet. All the tertiary reptiles approach the modern type, and all the present orders have their representatives in these deposits. It is remarkable that tertiary fishes of the same species are found in the most distant localities; such as the London clay of England, Monte Bolca in Italy, and in Lebanon in Asia. These fossil fishes resemble much those which are now found in the Indian Seas and in the Southern Ocean. The forms and shapes of some of these fossil fishes are emarkably unique. One genus h as, behind its head, a fin that rises like a tall mast much higher than the length of the ole body. From this mast of a fin, to the tail of the fish, there extends a corresponding sail, by the aid of which it was able to navigate its course in the tertiary seas. Another fish is so curiously formed that the height of its body and its fins is three times as much as the length of the animal. The various groups of tertiary fishes comprise many hundred species belonging to all the existing orders and families, of which nearly two hundred have been figured and described by Agassiz (pron. aggasee); of these forty or fifty belong to the family of the sharks, whose teeth are found in great abundance in the tertiaries. The ichthyological or "fishy" history of the tertiaries may be thus summed up. In the Eocene tertiaries one-third of the fish belong to extinct genera. In the newer tertiaries, such as the Crag, the races are of the genera common to tropical seas, and, throughout, the fossil fishes approach in their character to the living races, but all the species are extinct. REPTILES. The tertiary reptiles are of three classes-some inhabiting the land, others rivers, and others the brackish waters of estuaries; but they are all of a kind that prove the climate to have been of warm temperature. Among these, lizards and several kinds of crocodiles abound-so do also turtles and tortoises. But the most remarkable fact of this epoch is the existence of BIRDS. beds, several species have been found in the Paris basin, espeAlthough the remains of birds are very rare in the Eocene cially those resembling the pelican, the sea lark, the owl, the woodcock, and the buzzard. There have been some few and rare instances in which the fossil skeletons of birds have been well preserved. Cuvier. In some specimens he discovered even some fossil indications of feathers. In the lacustrine limestone of Auvergne in Central France, also the eggs of an aquatic species are found The first who discovered the fossil remains of birds was fossil. QUADRUPEDS. The land quadrupeds of the more ancient tertiaries are found fossil in much greater abundance in the gypsum beds of Paris than in the formations about London. There they include a great number of species chiefly of the group called Pachydermata, or the thick-skinned, represented now by the elephant, rhinoceros, etc.: but the most predominating are the carnivorous or flesh-eating quadrupeds, such as the wolf, fox, opossum, etc. In England also have been found a few fossil fragments of the teeth of creatures like the bat-and, what is most singular, of a monkey, as if, on Lord Monboddo's principles, approaches were made towards the production of man! All the fossil quadrupeds indicate a much warmer climate in their localities than are found now. The name of this group is derived from Taxvs, pachys, thick, and depua, derma, plural dermata, skins or hides. Among the Pachyderms were creatures allied to the horse, of which the tapir of South America seems now to be the best living representative. Another of the tapir group was an animal called the Lophiodon, of which only very imperfect frag ments have been found in a fossil state, but even those fragments point to the existence of more than twelve species. Its name is derived from Aopos, lophos, crest, and ddwv, odin, tooth, i. e, the Eocene. the crested-tooth. All these are supposed to have inhabited | timid animal. In external character it was the small deer of the dryer districts of the Eocene land. To the same group belong the better known fossil quadrupeds, the Palæotherium, and the Anoplotherium. The PALEOTHERIUM was much like the living tapir in the form of the head, having a short proboscis or trunk; but its molar teeth resembled those of the rhinoceros. It was about three or four feet high. Unlike the tapir, it had only three toes to each foot, and it was also very slender. An animal between the tapir and the horse would probably be a good representative of the Palæotherium, though its species varied greatly. It is supposed to have inhabited districts near water. The name is derived from Talaios, palaios, old, and Onpior, therion, a wild beast. The ANOPLOTHERIUM was less clumsy and more agile than the Palæotherium, and was a nearer approach to the ruminant group of animals. The Anoplotheria were abundant in the older tertiaries. The name is derived from a, (av before vowels,) privative, or without, ónλov, oplon, armour, and Onolov, therion, wild beast: that is the unarmed animal. Two species have been determined. These quadrupeds are represented in figs. 1, 2, 3, and 4 In the Meiocene and Pleiocene tertiaries we meet with the deinotherium, the mastodon, the elephant, etc. The DEINOTHERIUM, from devoç, deinos, terrible, and Onpiov, therion, a wild beast, was remarkable in size, in relation both to the anoplotherians of the older beds on the one hand, and to the elephantine groups of more recent periods on the other. The fossil remains of the Deinotherium are nowhere more common than in the valley of the Rhine, between Basle and Mayence, and they are also frequent in the valleys of the Jura. This animal was of a huge barrel-shaped body, and was twenty feet long, and in character was something like the hippopotamus. Its body was but little raised above the ground, though its legs were ten feet high. It lived in water, but its head was kept entirely out of the water. Its head resembled that of the elephant, having a powerful proboscis, and also a pair of large and long tusks curving downwards like those of the walrus. What is most remarkable in these tusks is, that they are fixed in the lower jaw of the animal, to enable it to dig for succulent 1. Anoplotherium gracile. 2. Anoplotherium commune. 3. Palæotherium magnum. 4. Palæotherium minus. The first species was about as tall as a dwarf ass, but its body was much longer, with the appendage of an enormous tail. It was particularly adapted to live in swampy districts and in marshes, where it fed on the roots and the leaves of aquatic plants. Its body was about eight feet long, with a skin nearly naked, and having its ears very short. Except the kangaroo, no living animal is known to have so long and so powerful a tail. food. It was the most gigantic of all the herbivorous or grasseating quadrupeds. The second species of Anoplotherium is called the Xiphodon, from Eipos, xiphos, a sword, and odov, odón, a tooth, a creature very different in size, in proportions, and in habits from the first species. The graceful elegance of its skeleton reminds one of the gazelle. It might be about as high as a goat, but its head and trunk indicate a smaller animal. It lived on the banks of lakes and rivers, and on the borders of marshes, feeding on aromatic herbs and the young buds of trees. It was covered with a short hair, and was most likely a The MASTODON was another species of elephant, about the size of the present elephants and with mammillated teeth. It abounded in the districts now called North America; where perfect skeletons of it have been found in salt marshes, which it visited for the sake of the salt, and where it frequently sunk in deep mud and perished. Some of these marshes are known to be forty miles long by about twenty miles broad. In Warren County, New Jersey, six skeletons of the same mastodon were found, six feet below the surface, five of them lying together. The name is given on account of its teeth being like paps from pastos, mastos, breast or pap, and odor, tooth. This species continued to live through the Pleistocene periods, almost down to the human epoch, accompanied by some of the animals which are now existing. LESSONS IN CHEMISTRY.-No. XXVI. (Continued from page 381, Vol. IV.) ALTHOUGH refined methods of producing condensation of vaporised products will be mentioned presently, I must first state that a very large number of chemical distillatory operations may be conducted by driving the vapour to be condensed into a flask or receiver, and cooling the latter by means of a piece of filter paper, wetted by the dropping upon it of water from a receptacle placed above, as represented in the accompanying diagram, fig. 20. Fig. 20. Whenever the extemporaneous manner of procedure will not succeed, more elaborate methods of effecting condensation must be had recourse to. Amongst these the most elegant, the most advantageous, and in every respect the best for all cases in which the cooling power of mere water suffices, is the refrigeratory apparatus fist devised by Baron Liebig, and known by his name. It is represented in our diagram, fig. 21, attached to the beak of a retort heated by a gas flame; in other words, the whole apparatus is represented in action. into the funnel-shaped tube, and thence to the lower end of the refrigerator. He will observe that water emerges from the other lateral bent tube and falls into a receiver. He will finally recognise the conditions and general arrangement of the apparatus to be such that a continuous stream of cold water is made to arrive in contact with the central glass tube, where, becoming heated, it rises to the upper portion of the metal tube, runs through the bent siphon-like pipe, and falls into a receiver. This instrument is of great utility to the chemist. It possesses very many advantages over the worm and tub. In the first place, it admits of being made of glass, whereas the tubworm is almost necessarily made of metal. Occasionally I am aware it is made of earthenware, as, for example, when employed in the distillation of nitric and hydrochloric acids, either of which would act upon metal. In the second place, the central tube in Liebig's apparatus admits of being readily cleansed by friction, and the eye glancing along a straight orifice can satisfy itself as to the state of purity; whilst, on the contrary, the cleansing of a tub-worm can only be effected imperfectly by means of rinsing. Thirdly, the apparatus of Liebig furnishes a continuous stream of cold water, whereas the tub-worm is merely cooled by contact with a stationary mass of water continually growing hotter. Finally, it is cheap, whereas the tub-worm is expensive; so regard it from what point of view we will, the advantages are all in favour of the apparatus of Liebig. Occasionally, however, water, although applied under the conditions most favourable to the exercise of its cooling properties, is not cold enough, in which case ice must be used, or a mixture of snow and ice, or, finally, some of those artificial cooling mixtures known to chemists. Many substances can only exist whilst exposed to excessive cold. Absolute pure prussic acid must be condensed by a mixture of ice and salt, and preserved surrounded by ice. Remove the icy protector, and the substance escapes in vapour. These general remarks will suffice to demonstrate the fact that the degree of cold necessary to produce condensation altogether depends on the volubility of the substance under treatment. Generally speaking, the cooling agency of water well applied suffices; occasionally the greater cold of ice is Fig. 21. The refrigerator consists of a metal tube, tin plate, brass, or copper, about 24 inches in diameter, and not less than two feet long, through which passes a glass tube a little longer than itself, and retained in the middle of the metal tube by means of two perforated corks, one at either end, the punctures being rendered water-tight by means of white lead cement. If the student now glances his eye at the metal tube he will discover that two bent tubes are attached to it externally and laterally, one towards either extremity. The student will also observe that water from the barrel or reservoir B trickles required, and, still more rarely, artificial cooling mixtures. During some of his experiments on the condensation of gases, Professor Faraday applied cold of such intensity that it is represented by some 240 or 250 minus degrees of Fahrenheit, whereas the freezing point cf water is +32° on the same scale! In addition to the modifications of the distillatory process already detailed, there are others dependent upon the nature of peculiar substances operated upon. Oil of vitriol, for example, is exceedingly difficult to be distilled in glass vessels. Its boiling point is high and its vapour is evolved in explosive starts dangerous to the safety of the apparatus; yet oil of vitriol may be safely distilled from a glass retort into a glass receiver by heating it in contact with fragments of platinum foil, and applying the distillatory heat in such a manner that the surface rather than the inferior strata of the fluid shall be vaporised. And first as regards the platinum foil, let me illustrate the effect of this substance comparatively. The reader has probably observed a glass of champagne which had ceased to effervesce, restored to its condition of primary effervescence by dropping into it a crumb of bread, a bit of cork, or almost any angular body. Now it is a general function of all solids, more especially pointed and angular solids, to promote the effervescence and ebullition of liquids into which they may be immersed; and, in this respect, metals, beyond all other bodies, are pre-eminent. Platinum, however, is one of the very few metals on which oil of vitriol does not act, and for this reason it is employed. The rationale of the action of solids in promoting the ebullition of liquids is not yet fully understood, although the result is well known and taken advantage of in many important operations. The peculiar method of applying heat so as to exercise its force on the upper rather than on the under layers of a liquid is represented by the annexed diagram, fig. 22, which repre Fig. 22. tion of which receives the sublimed solid, whilst the accompanying liquid sinks into the flask underneath. These general descriptions will suffice to give the reader a general notion of the nature and objects of distillation. The process, he will see, is one of remarkable simplicity, yet, strange enough to say, it appears to have been unknown to the ancient Greek and Romans, its origin being due to the Arabs. In stating that the Romans were unacquainted with distillation, I must be understood to limit the expression to distillation in our sense of the term, understanding it to apply to the compound operation of raising a liquid in vapour, and afterwards condensing that vapour in a refrigeratory apparatus. Nevertheless, a rude sort of distillation was occasionally followed by holding wool over the ascending fumes of a vaporising body, and thus effecting their partial imbibition. ON PHYSICS OR NATURAL PHILOSOPHY. (Continued from page 379, Vol. IV.) Language of Music.-In arranging musical sounds in regular order, it has been already observed that, after having expressed a certain number of them according to an ascending or descending scale, all other sounds are only a reproduction of these, modified only by their passing from low to high, or from high to low; so that they are still recognised to be the same sounds. The smallest distance which separates two sounds of this kind is called an octave. In the interval from one octave to another, it is easy to distinguish twelve different sounds placed at equal distances from each other. This distance is called a semitone, and the series of these twelve semitones is called the Chromatic Scale, from the coloured mark used by the Greeks to point out that the music was to be softened by lowering the sounds half a tone. This series, sents a retort supported by a hollow truncated cone of sheet- however, was simplified by the reduction of the scale to the iron let into a charcoal furnace in such a manner as to fit it seven natural notes or sounds of the Diatonic Scale, so called almost exactly. This arrangement is such that glowing char- because they were produced by the transversal vibrations of coal being placed between the cone and the furnace, as repre- strings stretched across any hollow musical instrument. To sented in the diagram, will heat the surface layers of the oil these seven sounds was added an eighth, which was the reof vitriol almost exclusively. As regards the refrigeratory petition of the first sound, in order to complete the octave. In part of this apparatus, the reader will see that a simple flask this scale, instead of proceeding regularly by equal semitones, without any contrivance for wetting it is alone employed. a series of full sounds and of alternate semitones was adopted; In point of fact, the condensation of oil of vitriol does not and its name, Gamut, is evidently derived from the French require such artificial aid, which, instead of proving service-word gamme (which means the same thing), with the addition able, would, in all probability, crack the receiver. of ut, the name of the first or lowest note in the natural scale. Occasionally a volatile solid is the subject of distillation, in which case the term sublimation is applied. The reader has more than once, whilst engaged in the investigation of arsenic, gone through the process of sublimation. Sometimes the result of distillation is partly a solid, partly a fluid, in which case a compound receiver, as represented in the subjoined diagram, fig. 23, is occasionally employed, the globular por Fig. 23. The sounds of the Gamut were originally indicated by letters, of which the lowest was the Greek T, Gamma, corresponding to our C; hence, the French word gamme, as the name of the scale of music. In the eleventh century, the names from ut to la were used instead of the letters, namely, ut, re, mi, fa, sol, la; and these names were taken from the first syllables of a religious hymn. Five centuries later, the note named si was added, and then ut repeated, which completed the series and the octave, as follows: C, D, E, F, G, A, B, C, ut, ré, mi, fa, sol, la, si, ut. Letters Names Notation.-There are two kinds of signs employed in musical notation; viz., those which express intonation, and those which indicate time or duration. The former are the notes; each note represents a distinct sound, and its value, that is, the time during which this sound is emitted. Five parallel straight lines at equal distances, with marks for the notes placed alternately on the lines and the spaces between them, constitute what is called the staff or stave, as in fig. 140, where the first octave is represented with the treble clef; the first note C being put upon a portion of a line called a ledger line. To this note, which is called ut, English musicians give the name of do. The place which a note occupies on the staff determines its intonation. The lower it is placed, the lower is its sound; and the higher it is placed, the higher is its sound. By a note being placed higher or lower here is meant, placed nearer to or further from the bottom of the page of a book, or of the face of a board placed vertically, on which the lines of the staff are drawn horizontally. It has been observed in our last lesson, that the terms low and high, with respect to sounds, are arbitrary and conventional; and that the real difference by which they are distinguished consists in this, that the sonorous body which yields a low sound makes, in a given time, a less number of vibrations than that which emits a high sound. The notes placed on the lower part of the staff represent, therefore, Fig. 140. Letters Names C, D, E, F, G, A, B, C, do, re, mi, fa, sol, la, si, do. sounds which are relatively lower than those do which are placed above them. The system of the gamut thus indicates that the notes rise to a greater height, as they are placed successively and alternately ascending from the lowest or first line of the staff;. then, on the space between the first line and the second; then, on the second line; next, on the second space; again, on the third line; next, on the third space; and so on. Yet, the distance which separates the sounds thus expressed is not regular; sometimes it represents a full sound, sometimes a semitone, as we have said, when speaking of the gamut. Sometimes the intervals between these successive sounds are called degrees. Two notes placed on the same line are said to be in unison; the interval from one degree to that which immediately follows it is called a second; the interval from the first degree to the third is called a third; and so on to the interval from the first degree to the eighth, which is called an octave; as explained in our last lesson. So much for intonation. A measure, in music, is a space of time, at the end of which the ear feels the want of rest; this rest forms the starting point of the following measure. The smallest portion of melody is always divisible by the ear into a certain number of measures, and each measure is divided into three or four times. The times are also divided into parts which may be either irregular or symmetrical, and this is what constitutes rhythm. In the on. The divided into two Quavers; the Quaver into two Semiquavers; and the Semiquaver into two Demisemiquavers; and so general rule for the relation subsisting between the length of these notes is, that each of the longer is double that of the shorter which follows it. The following table, fig. 141, exhibits the equivalent values and relative lengths of each note, with their corresponding times, and parts of a time. The Breve is a note seldom used, but of course it would contain eight times; it was denoted by the same character as a semibreve with two bars on each side of it, as shown in p. 183, vol. iv. col. 1, line 19. The measure containing four times may be conceived as divisible into two equal parts; but there are also pieces written in the measure containing two times. For this purpose no change is made in the system of signs just explained, except that the full measure, instead of being represented by a semibreve, is represented by a minim or its equivalents. As to the measure of three times, it is represented by a minim and a point alongside of it, as shown in the page and column above referred to, line 26, the point being employed to denote the prolongation of the duration during a third time. The point is used to lengthen all the other values of the notes; so that, when placed alongside a crotchet, a quaver, etc., it adds to their duration one-half of its original value. The Gamut. We have said that the diatonic scale proceeds by tones and semitones. By a full tone is understood the distance which separates any degree from that which immediately follows it, when this distance can be easily divided by the ear into two distinct sounds. In the contrary case, the interval is only a semitone. The diatonic scale is divided into five full tones and two semitones. In order to understand the position of both, we must consider the octave as composed of two equal parts, containing each four notes or degrees. Each of these parts, considered by itself, comprises two full tones and one semitone, to which must be added a full tone which separates the one from the other. Thus, in the first part, which extends from do or ut to fa, we find from ut to re a full tone, from re to mi a full tone, and from mi to fa a semitone. In the second, from sol to ut, we find between sol and la a full tone, from la to si a full tone, and from si to ut a semitone; lastly, if we join the two series, we find between fa and sol a full tone; which completes the construction of the octave. Whether this series of sounds be a consequence of the organisation of our auditory apparatus, or be the result of convention or of custom, it is no less true that the notes thus regulated are generally adopted system of notation, every measure is indicated by a bar perpendicular to the straight lines of the staff; consequently the assemblage of values comprised between two bars of this kind ought always to represent one equal period or duration divisible into equal times. The longest measure is that containing four times. The note which represents it in its whole duration is called a Semibreve. If this measure be divided into two notes of equal length or duration, these are call Minims; consequently, two Minims are equal to one Semibreve. When the same measure (that of the semibreve) is divided into four notes, each of them is called a Crotchet. The Crotchet is and satisfy all ears. On this point, therefore, viz. the construction of the scale, all the combinations and thrilling effects of modern music depend. Our remarks on the structure of the scale are especially applicable to that which begins at the note do or ut, and which is considered as the normal scale. But if we begin with any other note, with re' for example, it is plain that, in order to preserve the same ratios between the tones and semitones, it must be made to undergo a modification according to the intervals established in the scale of ut. These ratios are such that the semitones are found between mi and fa, and between si and ut, |