classification of the whole:-1st class are called Mr. Hunt, after describing the process introwaves of translation; 2d, oscillatory waves; 3d, duced by Mr. Pontor, by which negative photocapillary waves; 4th, sound-wave in water. graphs were produced on paper by the use of Of these the first is always solitary, the second the bichromate of potash, and the improvements and third always in groups; the first class has introduced by M. E. Becquerel, with a view to two varieties, positive and negative; the second the production of positive pictures, but which has also two, stationary and progressive. There process was tedious and very uncertain,-gave are no varieties in the third and fourth. Be- an account of his new process, the chromatype, sides these species there are the following sub-and exhibited very interesting specimens of picvarieties, the free and the forced wave, in each tures produced by it. The process, which is class. Such is the natural history or classifica- exceedingly simple, is as follows:-paper is tion of waves. Their principal characteristics washed over with a solution of the sulphate of noticed were-velocity, motion of particles, re-copper, dried, and then washed with a solution flection, and diffusion. 1. The velocity. The of the bichromate of potash. When dry these velocity of the first class is represented by papers are fit for use, and will keep for any ✔g (h+ k), where h is the height of the wave length of time unimpaired, if preserved in the and k is the depth of the channel. The velocity considerably varied, by which the shades of dark. The strength of the solutions may be of the second is 3.57 x ✓ length of wave; the colour of the finished picture are pleasingly velocity of the third is 8.5 inches per second changed. This paper is not recommended for the fourth is the well-known velocity of sound, 13.437. 2. The different kinds of motion of use in the camera obscura, but for all other purthe particles of water. In the first they un-botanical specimens, or the like, being laid on poses it is exceedingly useful. An engraving, dergo a permanent and final displacement; in the paper in a proper manner, it is exposed to the second an oscillatory or continued series of the sun's rays for a period varying, with the intemporary displacement; the third is the same. In the first the horizontal displacement is equal tensity of the light, from five to fifteen minutes. at all depths; in the second it diminishes ac- It is then washed over with a tolerably strong A very faint picture results from this exposure. cording to the depth; in the third it does not solution of the nitrate of silver, which brings out extend to a sensible depth below the surface of the water. In the first class the path of trans-and shades being correct as in nature. The only a very intense orange-colored image, the lights mission of all the particles is a semi-ellipse; fixing required is simple washing in pure water, in the second the displacement is a simple spi- and drying. If one of these chromatype pictures ral; in the third it is so minute as not to be as-is placed in a very weak solution of common certained. 3. Phenomena of diffusion and re-salt, it rapidly fades out, and the paper is reflection. The second and third classes are duced to its original whiteness. The picture, reflected according to the usual law. The first does not appear to suffer complete reflection; but however, is not obliterated; if the paper is held at considerable angles with the surface a curi- gradually come out, and the picture is restored; in the sunshine for few minutes, the images ous phenomenon is presented. If the angle which but instead of being of an orange color, it is now the ridge of the wave makes with the surface of the water be less than 30°, total reflection a fine lilac. This variety requires no fixing. takes place; from 30° to 60° it decreases, and ceases altogether from 60° to 90°; then, instead of being reflected, the wave advances forward, increasing in magnitude, until in a short time the whole wave is converted into another parallel to the surface. This phenomenon of nonreflection is peculiar to the wave of the first order. There is another curious phenomenon in waves of the first order; they are not diffused in circles round the point of generation, as in the common wave when a stone is thrown into the water; but from a given point there is always a direction in which the motion is most rapid; thus the path approaches an ellipse. The magnitude at different angles from the direction of greatest velocity has been ascertained: at 30° from the axis the intensity has diminished to a half, and at 45° to one-third of the greatest; thus the degradation follows a certain law. We cannot generate a wave of the first order except it be confined in a narrow channel. A stone dropped in the water will generate a wave of the second order, spreading equally in every direction. Capillary waves are in all cases confined to the surface of the liquid. Chemistry and Mineralogy.-R. Hunt on chromatype, a new photographic process; and on the influence of light on the growth of plants. Mr. Hunt's second communication was simply a statement of the results he had obtained since ed in the last volume of the Transactions of the the report which was made by him and publishAssociation. Most of the results were in confirmation of those already arrived at; and all went to prove the injurious effects of the luminous and calorific rays upon the young plant, and the energetic and healthful action of the chemithat the continued action of those chemical rays cal rays. The author had, however, discovered in a pure state, exerting a most powerful stimulating influence upon the plants, occasioned the and these of a fine dark color; but that the enproduction of an extraordinary amount of leaves, ergies of the plant being thus exhausted, it could This influence of the chemical rays on the vegenot be brought to flower, and speedily decayed. table world was similar to that exerted by pure noticed a remarkable property which he had oboxygen gas upon animals. The author also served in the luminous rays, namely, that under their influence agarics grew very rapidly, but not at all under the agencies of the other rays; which fact appears to correspond with the experience of gardeners, who attribute great power to the moon's rays in producing this variety of plants. The last paper was read by Prof. Kane. Prof. As closely bearing upon this subject, we may add here Mr. Hunt's paper read in Sect. B. on Saturday. Draper's theory is, that the decomposition of carbonic acid by the leaves of plants is effected by the luminous rays of the spectrum, and not by the chemical rays. For the purpose of prov- The object of Mr. Hunt's communication was ing that, he took a series of tubes, half an inch to show the high probability that the rays which in diameter and six inches in length, and ar- emanate from the sun are constantly acting upranged so that the colored spaces of the spec-on all bodies, and that but for our ignorance of trum fell on them. In those tubes water, im- methods by which the impressions can be pregnated with carbonic acid, and containing a brought out, we should be enabled to use any few green leaves, was placed. He supposed body as a photographic material. In addition that if the decomposition were due to radiant to those combinations which were well known to heat, the tube occupying the red space, or even possess photographic properties, the author callthe one in the extra spectral space at that end, ed attention to the wonderful additions made to would, at the close of the experiment, contain the list by Sir J. Herschel, who had shown that most gas; if to the chemical rays, in the violet, the salts of iron and of mercury were very rapidindigo, or blue; but if to the luminous rays, the ly changed by light; and nearly all kinds of gas should make its appearance in the yellow, vegetable juices were changed by its influence. with some in the green, and some in the orange. The author was now enabled to add the results The result proved his anticipations. In the tube of numerous experiments, all of which went to in the red space a minute bubble was sometimes prove the decomposing power of the solar rays. found, but sometimes none at all; in the orange In addition to the salts of silver ordinarily used, a considerable quantity; in the yellow a very it had been found that more than twenty combilarge amount comparatively; in the green a nations with organic acids gave very beautiful much smaller quantity; while in the blue, the results; and that the cyanate, and arseinate, and indigo, the violet, and extra spectral space on sulphuret of silver, previously considered as inthat side, not a single bubble was observed. He sensible, were really acted upon with great rastated that he decomposed the alkaline bicar-pidity. Combinations of gold with cyanogen, bonate by leaves in the sunshine-the effect not and benzoine, and many other bodies, proved being limited to the removal and decomposition the readiness of this metal to change in the of the second atom of the acid, but passing on to sun's rays. The salts of platinum were also the first-the neutral carbonate of soda itself de- found to be rapidly affected; and some pleasing composing, and yielding oxygen gas. He also photographs on papers prepared with combinamentioned an important improvement on the tions of platina were shown. Mr. Hunt had also tithonotype, and a new process of multiplying been successful in proving this change to take daguerreotypes. For the latter, his old plan place under the same influence on nearly all the was to evaporate to dryness on their surface, af- salts of copper-many of which changed rapidter being fixed by a film of gold, a solution of ly, and produced very pleasing pictures-and, as gelatine; but his new is to precipitate copper by far as they had been yet examined, on the salts the electrotype on the surface of the daguerreo- of manganese, of antimony, of tin, of lead, of cotype, after it has been fixed by gold. The cop-balt, and of arsenic. In addition to these, many per being much more tough than the gelatine, of the cyanates, the ferrocyanates, and the separates readily from the silver, and, when the iodides, with alkaline bases, were found to change operation is successful, bears a perfect represen- with considerable rapidity. Many of these pretation of the beauty and perfection of the origin-parations which had received photographic imal picture. Prof. Draper considers this method totally different from the attempt which many persons made to copy the daguerreotype by voltaic electricity, and that, in consequence of the ease with which they are made, the problem of multiplying the daguerreotype may be regarded as solved. ages were shown to the section; and the author expressed his regret that, from the fleeting character of some of the most interesting of these results, he was unable to do more than describe the effects. The author then detailed many very remarkable phenomena which were presented by reProfessor Apjohn questioned the results an-ceiving the impressions of the prismatic specnounced by Prof. Draper, and called on Mr. Hunt, who had experimented so much on the subject; who confirmed his opinion that the chemical and not the luminous rays were the most efficient in producing the decomposition of the carbonic acid absorbed by the plant. Mr. Hunt described his experiments on plants with colored glasses and with glass vessels filled with colored media; and, from every result he had observed, differed entirely from Prof. Draper. He would resume his study with the rays of the prism; and, in conclusion, he mentioned certain peculiarities in the vegetation of South America, which seemed to lead to the conclusion, that there existed a difference between the effects of light in southern and northern climes. *Assuredly the best method, and freest from suspicion of chemical interference.-Ed. L. G. trum upon different sensitive materials; all of which went to show the necessity of separating from light and also from heat that agent which was active in producing these changes which have been described. This element had its origin in the sun, and always accompanied the rays of light and heat; but its functions were different from either; and it appeared that we were on the verge of discovering an important power, which was ever active in maintaining that system of change which appeared to be constantly going on throughout the works of creation. Geology and Physical Geography.-The next paper read was by Messrs. Rogers, on the phenomena and theory of earthquakes, and connected with the same mountain range. The anticlinal flexures already alluded to were ascribed to a billowy movement of the earth's surface, like the phenomena attending an earthquake; and the two remarkable earthquakes which had occurred within the year were referred to as furnishing laws which confirmed in a striking manner the supposed origin of the Apallachian chain. All earthquakes consist of a remarkable motion, which is not simultaneous but progressive, and which moves parallel to itself from the source of disturbance. The author referred to the observations of Capt. Fitzroy and Prof. Mitchel in confirmation of his views, and dwelt on the phenomena attending the earthquake at Guadaloupe and Antigua, and also the earthquake at Lisbon. The zone of undulation extended in all directions, and at sea the sympathy seemed to be indicated by huge waves remarkably isochronous, propagated at the rate of five minutes after each other. Upon this hypothesis the American writers relied for the explanation of boulder stones, without resorting to the glacier theory. Mr. Hopkins questioned the law laid down for the organization of the Apallachian chain by Messrs. Rogers. A fluid mass beneath the earth might expand the outer crust, but would a horizontal force produce such power? A horizontal crust, with a reservoir of lava beneath, as in Vesuvius or Ætna, might cause a rising of the crust, assuming a curved form, but the elevation would produce fissuring, and it would be impossible to put it into the same form as before. The fluid matter would be forced into the fissures. Thus two causes would operate, lengthening by tension and injection. Besides, a wave was movable, and could not act in the way laid down, nor could the elevations correspond with successive waves. Mr. Phillips, Mr. Murchison, and Major Clerke, also spoke on the subject, and doubted the accuracy of the theory. Mr. Griffiths, on the great drift in Mayo and Sligo, noticed the position of the erratic blocks or boulders which occurred in these counties, as well as in other parts of Ireland. In the north part of the counties of Mayo and Sligo the current was from south to north, as was indicated by boulders of red sandstone from the Corlew mountains having been transported to the northward across the limestone valley of Ballymote to the base of the Ox mountains; and also, by large boulders of granite from the Ox mountains, some of them weighing upwards of 100 tons, being now found in great numbers on the surface of the limestone country to the north as far as the sea coast at Easky. Blocks of such large size were probably transported on ice, though it was remarkable that in this case, their direction was from south to north. They were so numerous, that when he first came to Ireland, he thought it was a granite, not a limestone country. It was well known that the removal of these blocks was accounted for in different ways-by currents-floats or drifts of ice-and glaciers. Limestone blocks might be transported by currents, but it was not so easy to account for the removal of the masses of granite. Sometimes shells were found on the tops of mountains, which could only be accounted for in this way, that these mountains had been once sub marine valleys, but by the up-heaving of the earth from some internal convulsion the present position was acquired. Mr. Lyell held that floating ice was capable of carrying larger blocks than any found here. When melted it might deposit these blocks in any place. This process was going on every day in large parts of Europe. The shells in Ireland and Scotland are found 700 feet high. Mr. Murchison agreed with Mr. Lyell as to the floating powers of ice. The great northern plains of Europe offered strong proofs of this. in Germany he had found large blocks on slight acclivities, bedded in earth. Mr. Hopkins gave an exposition of his views respecting the cause of the motion of glaciers. De Saussure had adopted and expounded the theory which attributes this motion to the resolved part of gravity acting along the inclined surfaces on which all glaciers in motion repose; and he explained also how the motion would be facilitated by the effects of the internal heat of the earth, and of subglacial currents. When the attention of philosophers, however, was recalled a few years ago to this subject, and more accurate observations and admeasurements were made, the inclinations of the beds of glaciers were found, in many cases, to be so small (in the glacier of the Alesch, for example, not exceeding three deg.) that it appeared extremely difficult to conceive how the force of gravity alone could be adequate to overcome the friction on the bottom and sides of the glacier, and the numerous local obstacles to its movement. Numerous experiments on the descent of bodies along inclined planes had shown, that, when the surfaces of the bodies and planes were perfectly hard and polished, no motion would ensue without an inclination considerably greater than that of many glaciers; and, moreover, that the inclination required to produce motion was independent of the weight of the sliding body. These considerations led to the very general rejection of De Saussure's theory, and to the adoption by many persons of the dilatation-theory, of which M. Agassiz had been the principal advocate. According to this theory, a part of the water produced by the dissolution of the superficial portion of the glacier during summer passed by infiltration into the minute pores and crevices of the glacier, when it was again converted into ice; and, by its expansion in the process of freezing, produced a dilatation and consequent motion of the glacier. It was manifest, however, that the frequent alternations of freezing and thawing within the glacier, which this theory assumed, could not possibly take place at depths beneath its surface exceeding a very few feet, and therefore could not produce any sensible effect on the motion of the whole mass. If the effect were referred to the freezing of water at greater depths, it could only be attributed at most to annual variations of temperature, and the consequent motion would take place during the colder season, or at its commencement, and not during the summer, when, as appeared by observation, the glaciers moved most rapidly. If, again, the dilatation were attributed to the freezing of the infiltrated water at still greater depths, where the temperature of the ice was unaffected even much sensibility as water itself. It will be observed in the results above given, that (1) the motion was unaccelerated; (2) it increased with the inclination, and (when the inclination was not greater than 90 or 10°) in nearly the same ratio; and (3) the rate of movement was of the same order of magnitude as in actual glacial motion, which may be stated generally, in cases yet observed, never to exceed two feet a day. by annual variations of the external temperature, and where consequently it was necessarily constant, how, it might be asked, were the internal pores and minute crevices of the ice to be again formed, when the infiltrated and subsequently frozen water had once filled these up, as it must necessarily do before it could produce a dilatation of the mass? No adequate solution had ever been given of these difficulties, and the author could not but consider this theory as being contrary to the most obvious mechanical and The extremely small friction between the physical principles; but while he expressed this plane and the ice indicated by the small inclinaopinion of the theory, he would also express his tion necessary to produce motion, was manifestsense of the important service which its distin-ly due to the circumstance of the lower surface guished advocate, M. Agassiz, had rendered to of the ice being in a state of gradual disintegrageology by the penetration with which he had tion, which, however, was extremely slow, as detected the effects of glacial action, and the proved by the small quantity of water proceedsteadiness with which he had maintained his ing from it. In the application, therefore, of general views on the subject. Another theory these results to the case of actual glaciers, it had also been put forward, which attributed the was necessary to show that the temperature of motion of glaciers to the expansion of water in their lower surfaces could not generally be less the act of freezing after it had filled, not the than 32° Fah. Such, the author stated, must minute pores of the ice, but internal cavities of necessarily be the case unless the conductive considerable dimensions. But, since the tem- power of ice was greater than it was deemed perature of the glacier at considerable depths possible that it could be. For the proof of this, must be sensibly constant, how were new cavi- and for other details, he referred to his memoir ties to be formed when existing ones were thus on the subject recently read before the Camfilled up, if the cause now assigned were the bridge Philosophical Society. He also considerprincipal cause of glacial motion? The authored the subglacial currents as powerful agents in always regarded both this theory and the pre- the disintegration of the lower surfaces of glaceding one as totally untenable; and was thus ciers, especially near their lower extremities. led to examine how far the apparent objections to De Saussure's theory were really valid by a series of experiments on the descent of ice down inclined planes. The experiments were made in the following manner:-a slab of sandstone, pre-ed. pared to be laid down as a part of a common flagstone pavement, was so arranged as to be easily placed at any proposed inclination to the horizon. The surface of the slab, so far from being polished, retained the grooved marks of the instrument with which the quarryman had shaped it. A quantity of ice was placed on the slab, and within a frame nearly a foot square, without top or bottom, and merely intended to keep the ice together without touching the slab, with which the ice alone was in contact. The following were results obtained in one set of experiments, the ice being loaded with a weight of about 150 lbs.: Inclina Spaces in decimals of an inch through Mean space tion of which the loaded ice descended in sucfor one plane. cessive intervals of ten minutes. hour. Soon after the reading of the memoir above referred to, a work had appeared on the glaciers of the Alps by Prof. Forbes, the descriptive details of which could not be too highly commend The results of his observations on the motion of the Mer de Glac of Mont Blanc afforded, as regarded that glacier, (and by inference as regards all other glaciers,) a complete refutation of the theories which attribute glacial movements to any expansion or dilatation of the ice. In this work, Mr. H. stated, the professor had put forth a new theory, which agreed with that offered by himself in attributing glacial motion to the action of gravity, but differed from it entirely as a mechanical theory in other respects. The author appeared to reject the sliding theory of De Saussure on account of the difficulties already mentioned, (which were now removed by the above experiments,) and assigned to the mass of a glacier the property of plasticity or semifluidity in a degree sufficient to account for the fact of its descending down surfaces of such small inclination. Thus, according to this theory, the motion was due to the small cohesion of one particle of glacial ice to another; while, according to the views now offered, the motion was due to the small cohesion of the lower surface to the bed of the glacier: the smallness of the latter cohesion had been proved by the experimental results above stated, that of the former appeared opposed to all observation, and was wanting When the weight was increased, the rate of in all experimental verification. Mr. H. stated motion was also increased: the least inclination his conviction that the internal cohesion of the at which sensible motion would take place was mass was immensely greater than its cohesion not determined, but it was ascertained that it to the surface on which it rests whenever the could not exceed half a degree in the case of a lower surface is in a state of disintegration. It smooth but unpolished surface. With a polished was perfectly consistent with this conclusion to surface of a marble slab, the motion of the ice in-assign to the glacier whatever degree of plasdicated a deviation from horizontality with asticity might be necessary to account for the reVOL. III. No. III. 27 30 08 05 07 03 04 05 07 06 ·04 31 6 09 10 09 07 08 •52 9 14121714 ·19 ·20 .96 12 38 34 36 27 2.0 15 43 41 20 The mass descended with an 2.5 lative motions of its central and longitudinal portions, under the enormous pressures to which, according to his theory, he showed it might be subjected. Such relative motions, however, were probably facilitated more by the dislocation than the plasticity of the mass. For a complete mechanical exposition of his views, he must again refer to the memoir already cited. Sufficient, he trusted, had been advanced to prove that the sliding theory assigned a cause adequate to the production of all the observed phenomena of glacial movements. scattered over the plains, seems almost to confirm beyond further question the truth of the inferences drawn from these data. Col. Sabine also read a letter, stating that in the mountains to the N. W. of Bantry numerous traces of former glacier-action were to be seen. Mr. Peach then read the following report :The object of this paper is to lay before you information which, connected with the other discoveries made of the fossil organic remains of Cornwall, may give to the rocks a "name and habitation" in the geological scale, which for With respect to the transport of erratic blocks some time past they have not had, without both and detritus of the Alps to the Jura, Mr. Hop-being disputed. I do not place my hopes so high kins observed that the greatest height which as to say that I shall do either positively; at any glaciers had formely attained in the valley of the rate, I believe there is now strong presumptive, Rhone (whence a large portion of the erratics if not positive, evidence, which will induce you had been derived) appeared to be well defined to come to a better finding than has been done by lateral moraines and polished rocks, while by the late trials on the subject. Hoping this, I the greatest height at which these blocks had have come over for the purpose of hearing the debeen deposited on the Jura was also well defin- cision, and being at the christening. In Messrs. ed. Thus, according to M. Charpentier, the Murchison and Sedgwick's paper, in the GeoRhone glacier must have risen at the mouth of logical Transactions, vol. v., new series, I find, the valley to about 2500 feet above the existing when speaking of the rocks of Polperro, they surface of the Lake of Geneva, while the high-say, "As the same prevailing northern dip is est band of detritus on the Jura was stated to continued to the mouth of the Fowey river, it is rise to a still higher level. It was inconceivable, obvious that the beds above described are infetherefore, that such detritus should have been rior to the fossiliferous group." Some time ago lodged at its present elevation by former gla- I received from the Messrs. Couch, surgeons of ciers. The only way in which it appeared pos- Polperro, in a letter, two or three pieces of what sible to obviate the mechanical difficulties of the they considered coral from the rocks of their subject was, to suppose the transport to have neighborhood. I thought them interesting, but been effected when the Jura was at a lower could not agree with them that they were coral, level relatively to the Alps, and the whole dis-and gave my opinion that they were portions of trict lower relatively to the surface of the ocean. In such case, the space between the Alps and the Jura may have been occupied by the sea, and the ice, with its transported materials, may have passed from the former to the latter chain, partly with the character of a glacier, and part ly with that of an iceberg. This hypothesis is perfectly consistent with the supposition of the general configuration of the surface of the Jura having been the same at the epoch of transport as at the present time; and Mr. H. believed it would be found equally so with all the observed phenomena of that region. bone, and probably fish-bone. These gentlemen were both opposed to me, and said, "that they knew of no bone with such a structure." This added strength to my suspicions, from having somewhere gleaned, "that the structure of the fossil fishes of the older rocks agreed with that of no known existing ones." I felt determined, if possible, to examine these rocks. On the 20th of June last I did so, accompanied by Mr. R. Q. Couch, when, to my inexpressible delight, I found a large and extensive fish-bone bed, extending east and west of Polperro, containing immense quantities of portions of the cephalasCol. Sabine read a letter from an officer of the pis and onchus of the old red sandstone, with a antarctic expedition, stating that in the lat. 79° few other indistinct and ill-defined shells; also they had met immense cliffs of ice, forming the portions of the skin or shagreen of the sphægodes, sea-borders of an enormous glacier, above which, &c. of the upper Ludlow rock, all figured and at a great many miles distance, the tops of the described in Mr. Murchison's silurian remains. mountains were visible. The ice-cliff was con- These remains are found in the rocks described stantly breaking and tumbling down, and the in their paper, quoted above, with the "transdisjoined masses congregated and floated away verse fracture," and placed by them as "inferior to the north to the 60th degree of lat., where an to the fossiliferous group." I must beg of you enormous extent of icebergs were constantly to to bear with me a very short time longer, just to be found floating and not fixed to any submarine say, that when I had the honor of reading my ridge. Here they were constantly depositing, paper before this section at Plymouth, I menby their dissolution, immense quantities of stones, tioned my having found "fish-bones," and also earth, and other materials brought from the dis-" remains of a fossil, the structure of which retant mountains of the antarctic region. The re-sembled sepiadæa ;" and although I could not markable analogy of this great extent of glaciers convince you then of such being the fact, from and iceberg action to the presumed processes supposed to have taken place on the earth dur ing the distant cold period, of which the traces remain in the elevated ridge of boulders at a height of 2500 feet above the present glaciers in the Alps, with the marks of scratching and polishing on the Alpine tops, and the erratic blocks the obscurity of the specimens then produced, I never could banish from my mind the fossil fish of Cornwall. Now I believe I may say without doubt, the specimens I produce give proof positive that I then had truth on my side; and if I feel highly delighted with the discovery, I trust I shall be pardoned. I will just mention that I |