Search Results - The Complete Work of Charles Darwin Online

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A764 Beagle Library: Daubeny, Charles. 1826. A description of active and extinct volcanos. London: W. Phillips. Text

constant and essential ph nomenon of an active volcano, is the evolution of certain aeriform fluids, which, forcing themselves a passage through the incumbent strata, carry up with them whatever comes within the sphere of their violence, thus giving rise to ejections of stones, of ashes, and even of water. To determine the chemical nature of these gases, and to ascertain by an extensive induction of particulars, which of them are to be considered essential, and which as arising out 2 A 2 [page] 37

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A764 Beagle Library: Daubeny, Charles. 1826. A description of active and extinct volcanos. London: W. Phillips. Text

, which was covered by a crust of very pure sulphur, 18 inches in thickness, broken open on the northern side, through which the vapours issued. * Is not this what Livy refers to, when he speaks of clouds of wool being seen to rise from the ground at Privernum (now Piperno), Priverni lana pulla terr enata, 1. xlii. c. 2. Julius Obsequens notices a similar ph nomenon at Pr neste (Palestrina) c. 140 and c. 89. It is probable, that the evolution either of muriatic acid or of muriate of ammonia, gave

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A764 Beagle Library: Daubeny, Charles. 1826. A description of active and extinct volcanos. London: W. Phillips. Text

which they appear to occur: in the first place, so long as air was present, an evolution of large volumes of muriatic, sulphurous, and nitrogen gases, together with aqueous vapour, would take place; at a later period, when the oxygen was expended, sulphuretted hydrogen and carbonic acid, with a smaller quantity of muriatic acid, would appear; lastly, when all the other effects had subsided, aqueous vapour and carbonic acid might continue to be evolved. If it be asked, how we can account for the

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A764 Beagle Library: Daubeny, Charles. 1826. A description of active and extinct volcanos. London: W. Phillips. Text

as the first effect of the heat would be to produce a softening of the contiguous strata, it must necessarily happen, that the evolution of so large a portion of elastic matter would have the effect of bearing them up to a certain distance round the focus of the volcanic action.* This aperture would undoubtedly be filled in the first instance by the gases given off by the volcano itself, but the slightest intermittence, or even inequality in the process would occasion a partial vacuum, which

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A764 Beagle Library: Daubeny, Charles. 1826. A description of active and extinct volcanos. London: W. Phillips. Text

volcano. It may be remarked, that in the cases alluded to, the basalt is always seen covered by a bed of scori or some other substance, which might have prevented the too sudden abstraction of heat. There is also this further distinction. In antient volcanic products no difference of compactness or texture exists between the upper and lower portions of a bed, such as would indicate a more sudden cooling or a greater evolution of elastic matter in the superficial portions, as is generally the

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A761.06 Beagle Library: Cuvier, Georges. 1827-35. The animal kingdom arranged in conformity with its organization. With additional descriptions of all the species hitherto named, and of many not before noticed, by Edward Griffith and others. 16 vols. London: Geo. B. Whittaker. vol. 6: Aves (1). Text

acting on the organs in a propelling direction to the external surface in proportion as reparation takes place. This mutation or evolution of living beings is the source of the changes which their external surfaces undeigo in the different periods of their existence. These changes are of great importance to study inasmuch as' an ignorance of them has often caused the multiplication of species and confusion of sexes and distinctions in many instances where there was no real difference. The

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A761.09 Beagle Library: Cuvier, Georges. 1827-35. The animal kingdom arranged in conformity with its organization. With additional descriptions of all the species hitherto named, and of many not before noticed, by Edward Griffith and others. 16 vols. London: Geo. B. Whittaker. vol. 9: Reptilia. Text

The tadpole then is a young batracian, from the moment in which it issues from the egg, until, after various metamorphoses, it passes to the adult state, without preserving either its form, structure, or even its mode of living. When we examine the different periods of its evolution in the eggs of frogs, (which of all the eggs of reptiles have been the most carefully studied, as to the development of germs,) we find that during the three or four days which follow the fecundation, the tadpole

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A761.17 Beagle Library: Cuvier, Georges. 1827-35. The animal kingdom arranged in conformity with its organization. With additional descriptions of all the species hitherto named, and of many not before noticed, by Edward Griffith and others. 16 vols. London: Geo. B. Whittaker. vol. 17. Text

The tadpole then is a young batracian, from the moment in which it issues from the egg, until, after various metamorphoses, it passes to the adult state, without preserving either its form, structure, or even its mode of living. When we examine the different periods of its evolution in the eggs of frogs, (which of all the eggs of reptiles have been the most carefully studied, as to the development of germs,) we find that during the three or four days which follow the fecundation, the tadpole

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A829 Beagle Library: Thompson, John Vaughan. 1828. Zoological researches and illustrations: or, natural history of nondescript or imperfectly known animals, in a series of memoirs. Volume 1, Pt 1. Cork: King and Ridings. Text

animal; the third and last pair of rowers are also slightly lobed beneath, and furnished with a few bristles. At the end of several days, no other alteration takes place in the animal than the more complete developement of its rowers, and the elongation of its tail, which appears slightly indented at the sides: Pl. 2, f. 8, it is still a Monoculus, or provided with but one sessile eye. As its growth and evolution go on progressively, it is observed to acquire a pair of sessile eyes, in addition

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A829 Beagle Library: Thompson, John Vaughan. 1828. Zoological researches and illustrations: or, natural history of nondescript or imperfectly known animals, in a series of memoirs. Volume 1, Pt 1. Cork: King and Ridings. Text

rapidity with which one brood succeeds to another during the whole of the spring and summer months: the number of broods produced by one individual, as well as the time occupied in their evolution, have not been determined, but the changes which the embryo undergoes in configuration are sufficiently obvious; in the present instance, these cannot be considered as metamorphoses, but simply a gradual developement of parts, hence the Shizopoda may be regarded as one exception to the Crustacea

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A829 Beagle Library: Thompson, John Vaughan. 1828. Zoological researches and illustrations: or, natural history of nondescript or imperfectly known animals, in a series of memoirs. Volume 1, Pt 1. Cork: King and Ridings. Text

sary with nutrition to the continuance of life and the evolution of the f tus, as the subgelatinous secretion appears to exclude the direct influence of the ocean upon the respiratory organ, which moreover does not appear to be developed until the moment prior to their exclusion from the pouch, this circumstance, taken in conjunction with the suspicions of some Physiologists as to the oxigenation of the f tal blood, may lead to such further observations as may tend to throw some new light upon

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A829 Beagle Library: Thompson, John Vaughan. 1828. Zoological researches and illustrations: or, natural history of nondescript or imperfectly known animals, in a series of memoirs. Volume 1, Pt 1. Cork: King and Ridings. Text

, went through their several stages of evolution, and finally attained to near their full growth. The Artemis Salinus or Brine Shrimp, is a very small and delicate animal, when full grown about half an inch in length, of considerable transparency, slightly tinged with yellow, and with a highly polished surface; nature having constructed them with members solely adapted to swimming, they seem to be in perpetual pursuit of prey, gliding with an almost even motion through the water, and moving with

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A914 Book: Lawrence, John. 1829. The horse in all his varieties and uses. London: Longman, Rees, Orme, Brown & Green. Text

ruffing the outside heel to prevent slipping, to which Mr. Goodwin objects. Certainly hunting shoes should be concave on the ground surface. I cannot laud the prudence of him who rode Lord Maynard's mare in the field (Goodwin, p. 219), when she performed so completely the evolution of overreaching, whence he must have known she went hammer and pinchers together, surely a most improper and dangerous form for a hunter. Mr. Goodwin says, if the inward edge of the hind shoes are bevelled and rounded, this

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A919.3 Beagle Library: Richardson, John. 1829-1836. Fauna Boreali-Americana. 3 vols. London: John Murray. Volume 3. Text

the deepest and saltest water of the estuary. The following observations on the spawning of the salmon, and subsequent evolution of the young fry, in one of the tributary streams of the Tweed, are recorded by Dr. Knox in the paper we have already cited. In November the river Whitadder, which has its source in a mountainous country nine hundred feet above the level of the sea, abounded in all the different kinds of salmon usually taken in the Tweed, with which this stream communicates at a short

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A913 Beagle Library: Kater, Henry and Lardner, Dionysius. 1830. Mechanics (Lardner's Cabinet cyclopaedia). London: Longman, Rees, Orme, Brown & Green. Text

of it. Elasticity of it. Liquids not absolutely incompressible. Experiments. Elasticity of Fluids. Aeriform Fluids. Domestic Fire Box. Evolution of Heat by compressed Air. 9 CHAP. III. INERTIA. Inertia. Matter incapable of spontaneous Change. Impediments to Motion. Motion of the Solar System. Law of Nature. Spontaneous Motion. Immateriality of the thinking and willing Principles. Language used to express Inertia sometimes faulty. Familiar Examples of Inertia. 27 CHAP. IV. ACTION AND REACTION

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A505.1 Beagle Library: Lyell, Charles. 1830. Principles of geology, being an attempt to explain the former changes of the earth's surface, by reference to causes now in operation. 3 vols. London: John Murray. vol. 1. Text

convulsions, and that fissures have opened from which hot vapours, thermal springs, and at some points red hot liquid lavas have issued to the surface. This evolution of heat often continues for ages after the extinction of volcanos and after the cessation of earthquakes, as in Central France, for example, and it seems perfectly natural, that each part of the earth's crust should, as M. Fourier states to be the fact, present the appearance of a heated body slowly cooling down. This may be owing chiefly

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A505.1 Beagle Library: Lyell, Charles. 1830. Principles of geology, being an attempt to explain the former changes of the earth's surface, by reference to causes now in operation. 3 vols. London: John Murray. vol. 1. Text

villages on the flanks and at the foot of the mountain. Resina, partly built over the ancient site of Herculaneum, was consumed by the fiery torrent. Great floods of mud were as destructive as the lava itself, as often happens during these catastrophes; for such is the violence of rains produced by the evolution of aqueous vapour, that torrents of water descend the cone, and, becoming charged with impalpable volcanic dust, roll along loose ashes, acquiring such consistency as to deserve their

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A505.1 Beagle Library: Lyell, Charles. 1830. Principles of geology, being an attempt to explain the former changes of the earth's surface, by reference to causes now in operation. 3 vols. London: John Murray. vol. 1. Text

the sun's disk, and a haziness in the air, often continued for months; an evolution of electric matter, or of inflammable gas from the soil, with sulphureous and mephitic vapours; noises underground, like the running of carriages, or the discharge of artillery, or distant thunder; animals utter cries of distress, and evince extraordinary alarm, being more sensitive than men of the slightest movement; a sensation like sea-sickness, and a dizziness in the head, are experienced: these, and other

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A505.1 Beagle Library: Lyell, Charles. 1830. Principles of geology, being an attempt to explain the former changes of the earth's surface, by reference to causes now in operation. 3 vols. London: John Murray. vol. 1. Text

, serve as permanent vents of heat generated in the subterranean regions. The plentiful evolution, also, of carbonic acid, from springs and fissures throughout hundreds of square leagues, is another regular source of communication between the interior and the surface. Steam, often above the boiling temperature, is emitted for ages without [page] 47

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A505.2 Beagle Library: Lyell, Charles. 1830. Principles of geology, being an attempt to explain the former changes of the earth's surface, by reference to causes now in operation. 3 vols. London: John Murray. vol. 2. Text

belief prevalent amongst the older naturalists, that the primeval ocean invested the whole planet long after it became the habitation of living beings, and thus he was inclined to assert the priority of the types of marine animals to those of the terrestrial, and to fancy, for example, that the testacea of the ocean existed first, until some of them, by gradual evolution, were improved into those inhabiting the land. These speculative views had already been, in a great degree, anticipated by