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A922
Beagle Library:
Somerville, Mary. 1834. On the connexion of the physical sciences. London: John Murray.
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development of heat. Instead of a momentary evolution, which seems to arise from a forcible compression of the particles of matter during the passage of the common electric fluid, the circulation of the voltaic electricity is accompanied by a continued development of heat, lasting as long as the circuit is complete, without producing either light or sound; and this [page] 30
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A922
Beagle Library:
Somerville, Mary. 1834. On the connexion of the physical sciences. London: John Murray.
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however, somewhat different, for, although the evolution of the electricity is continued for a sensible time, it is interrupted, being communicated by a succession of discharges. SECTION XXX. IN order to explain the other methods of exciting electricity, and the recent discoveries that have been made in that science, it is necessary to be acquainted with the general theory of magnetism, and also with the magnetism of the earth, the director of the mariner's compass, and his guide through the
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A922
Beagle Library:
Somerville, Mary. 1834. On the connexion of the physical sciences. London: John Murray.
Text
juxtaposition as by contact; the nature of the poles depends upon the direction of the current, and the intensity is proportional to the quantity of electricity. It appears from what precedes, that the principle and characteristic phenomena of the electromagnetic science are, the evolution of a tangential and rotatory force exerted between a conducting [page] 33
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A922
Beagle Library:
Somerville, Mary. 1834. On the connexion of the physical sciences. London: John Murray.
Text
varies inversely as the square of the distance. The development of electric currents, as well by magnetic as electric induction, the similarity in their mode of action in a great variety of circumstances, but above all the production of the spark from a magnet, the ignition of metallic wires, and chemical decomposition, show that magnetism can no longer be regarded as a separate, independent principle. That light is visible heat seems highly probable; and although the evolution of light and heat
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A900
Beagle Library:
De La Beche, Henry Thomas. 1834. Researches in theoretical geology. London: Charles Knight
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carburetted hydrogen, in the vesicles of coal, no small volume must occur in this state. In this account we must not neglect the hydrogen evolved from volcanos, either in aqueous vapor, or combined with other substances in a gaseous form. It would appear, however, that the evolution of hydrogen, either from volcanos, or from fissures in the rock, in the shape of inflammable gases, produces little effect on the atmosphere, so that either the general amount must be inconsiderable, or it unites with the
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A894.2
Beagle Library:
Webster, William Henry Bayley. 1834. Narrative of a voyage to the southern Atlantic Ocean, in the years 1828, 29, 30, performed in H.M. Sloop Chanticleer. 2 vols. London: Richard Bentley. Volume 2.
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abundant at St. Helena, in veins among the lofty ridges of basaltic rock; but it may in these cases have a different origin, and be a true igneous formation, from the evolution of sulphureous acid coming in contact with the earthy base; and thus form anhydrous gypsum; for we had sulphur and alum at South Shetland with the gypsum. Here we have demonstration of its marine origin, forming extensive beds, and crystallizing in a variety of ways; we have likewise evidence of the contemporaneous [page
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A900
Beagle Library:
De La Beche, Henry Thomas. 1834. Researches in theoretical geology. London: Charles Knight
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Now the volcanic eruptions of the moon must be very different from those on the surface of the earth, if they be not accompanied by the evolution of gas. If gases be evolved in lunar volcanic eruptions, gravity necessarily brings them down on the moon's surface, and they can only disappear from thence, either by combining with liquid or solid matter, by the influence of intense cold, or by the effect of considerable pressure. Pressure on the moon's surface can only arise from the attraction of
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A900
Beagle Library:
De La Beche, Henry Thomas. 1834. Researches in theoretical geology. London: Charles Knight
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eventually constitute a considerable part of an atmosphere principally composed of nitrogen and oxygen. As it is no part of our intention to conceal difficulties, it must be stated that to suppose carbonic acid originally and in a great measure confined to a gaseous envelope of our planet, does not well accord with the production of limestones, nor with the evolution of this gas from volcanos, fissures in the earth, and from springs. It would, indeed, accord with the views of M. Adolpbe
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A900
Beagle Library:
De La Beche, Henry Thomas. 1834. Researches in theoretical geology. London: Charles Knight
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gen evolved. Supposing the water with the contained air to come into contact with such substances as sodium and potassium, we should expect to have at least a decomposition of part of the water, and a consequent evolution of hydrogen. Now as hydrogen, either free or combined with substances other than oxygen, and then constituting the water itself, is not found in all thermal springs, though it is present in some, we are led to conclude that the union of oxygen with a metallic base causing
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A900
Beagle Library:
De La Beche, Henry Thomas. 1834. Researches in theoretical geology. London: Charles Knight
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of carbonic gas; and we see that the Carlsbad water, with a temperature of 165 Fahr., contain five cubic inches of this gas in a wine pint,* while those of Pyrmont are impregnated with it to the amount of twenty-six cubic inches in the same measure, the spring not being thermal. One of the great characteristics of volcanic action is the violent evolution of gaseous matter and aqueous vapor. Possibly some of the latter may be produced by an union of free hydrogen with the oxygen of the
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A900
Beagle Library:
De La Beche, Henry Thomas. 1834. Researches in theoretical geology. London: Charles Knight
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temperature at different depths. As nitrogen has never yet been liquefied by experiment, we do not know that it would become so beneath the water of any part of the ocean; but though it may not become liquid beneath such pressure, it would, being elastic in its gaseous condition, be rendered so dense as to be subject to those effects which have been attributed to atmospheric air under similar circumstances. The evolution of vapors and gases, and the causes which may have produced them, are
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A900
Beagle Library:
De La Beche, Henry Thomas. 1834. Researches in theoretical geology. London: Charles Knight
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time; that is, we should expect the hydrogen evolved to escape through fissures, accompanied by fused rock and various gases and vapors. Such an hypothesis might plausibly explain the elevations of parts of Italy, but appears inadequate to account for the remarkable rise of land, within historical times, noticed in Norway and Sweden, it being unaccompanied by the evolution or ejection of gases or other substances, which might lead us to believe that decomposition of water beneath, from the
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(a) Till this idea occurred to me, I had often been puzzled to explain presence of rounded pebbles of the subaqueous lavas, which I believed had been produced in deep water. A crater full of water, fragments of rocks, ( bombs) mud would by the constant evolution of gases during the semi-active phases cause much attrition; which during an eruption would together with angular pieces of lava (or inferior strata) be scattered abroard. N B. I believe amongst the 10 specimens one will be found of
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F1577
Periodical contribution:
Barlow, Nora ed. 1963. Darwin's ornithological notes. Bulletin of the British Museum (Natural History). Historical Series 2 (7): 201-278. With introduction, notes and appendix by the editor.
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procrastination over the other volumes that the actual publication was delayed until 1839. Here is concrete evidence that the Ornithological Notes were finished before March, 1837, for they were then being used as material to dove-tail into the script for Messrs. Colburn. Thus it is interesting to note that Darwin did not begin his first Evolution Notebook, dated 1837, until after he had got the MS. of the voyage off his mind.5 Darwin, therefore, either assembled his ornithological data of the voyage after
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F1577
Periodical contribution:
Barlow, Nora ed. 1963. Darwin's ornithological notes. Bulletin of the British Museum (Natural History). Historical Series 2 (7): 201-278. With introduction, notes and appendix by the editor.
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ideas were constantly both guiding and receiving feed-backs from his observations during the vital South American years of the voyage. It is as though he were on the bank of a stream, discovering that all the floating straws were pointing one way; the stream of evolution explained a whole concourse of facts. In the drafts, stages I to III, described in this Introduction, many of these signs are at first only dimly apprehended; with Darwin's increasing certainty, species and their distribution in
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F1577
Periodical contribution:
Barlow, Nora ed. 1963. Darwin's ornithological notes. Bulletin of the British Museum (Natural History). Historical Series 2 (7): 201-278. With introduction, notes and appendix by the editor.
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filled by other types of specimens. The ornithological portions are what Darwin had in front of him when compiling the O.N.s, and indeed he often copied passages almost verbatim. If it is now agreed that the O.N.s were written during the last months of the voyage, apart from the additions clearly made when within reach of expert opinion in England, then changes of Darwin's point of view or traces of early pointers towards evolution, may still be found in these volumes 30 and 31, which ante-date
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F1583e
Periodical contribution:
Herbert, S. ed. 1980. The red notebook of Charles Darwin. Bulletin of the British Museum (Natural History) Historical Series 7 (24 April): 1-164.
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the Macrauchenia. It is also essential for the larger purpose of establishing a date for Darwin's arrival at a belief in the mutability of species. On this last point it should be stated that while Darwin's observations during the Beagle voyage were fundamental to his work on evolution, his notes from the voyage do not reveal him to have been an evolutionist. He was at the stage of asking basic questions.5 It should also be stated that there has previously been no fully satisfying evidence to
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F1583e
Periodical contribution:
Herbert, S. ed. 1980. The red notebook of Charles Darwin. Bulletin of the British Museum (Natural History) Historical Series 7 (24 April): 1-164.
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his theory of evolution through natural selection was at a meeting of the Linnean Society held on 1 July 1858. For an assessment of the meeting see J. W. T. Moody, 'The reading of the Darwin and Wallace papers: an historical non-event ', Journal of the Society for the Bibliography of Natural History, vol. 5 (1971), p. 474-476. The resultant publication with Alfred Russel Wallace appeared under a general title as: 'On the Tendency of Species to Form Varieties; and on the Perpetuation of Varieties
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F1583e
Periodical contribution:
Herbert, S. ed. 1980. The red notebook of Charles Darwin. Bulletin of the British Museum (Natural History) Historical Series 7 (24 April): 1-164.
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(1967), pp. 162-163. Darwin's earliest draft of his theory was his 'Sketch' of 1842, followed by his lengthier Essay of 1844. For these see Charles Darwin and Alfred Russel Wallace, Evolution by Natural Selection (with a foreword by Sir Gavin de Beer) (Cambridge, 1958). In 1856 Darwin began his longest exposition of his argument. For the reconstructed text of this version see R. C. Stauffer, ed., Charles Darwin's Natural Selection (Cambridge, 1975). The theory finally came before the public in 1858
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against the formation of species are absurd. The argument about the evolution of the otter through intermediate forms is developed in the Essay of 1844, p. 152. [deB] 2 Leonard Jenyns, afterwards Blomefield. Probably personal communication. [deB] 21
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