scholarly journals XX. Researches in physical geology

1839 ◽  
Vol 129 ◽  
pp. 381-423 ◽  

Before I proceed to the discussion of the question which forms the principal sub­ject of the present communication, I shall offer some general remarks on the refri­geration of the globe, as introductory not only to this memoir, but to others which I hope hereafter to bring under the notice of the Society. In the first place, we may observe that there are two distinct processes of cooling, of which one belongs to bodies which are either solid or imperfectly fluid, and is termed cooling by conduction , and the other to masses in that state of more perfect fluidity which admits of a free motion of the component particles among themselves. In this case the cooling is said to take place by circulation or convection . The na­ture of the former process has been ascertained with considerable accuracy by ex­periment, and the laws of the phenomena have been made the subject of mathematical investigation, but of the exact laws of cooling by the latter process we are compara­tively ignorant. It is manifest, however, that since time must be necessary for the transmission of the hotter and lighter particles from the central to the superficial parts of the mass, as well as for that of the colder and heavier particles in the oppo­site direction, the temperature must increase with the depth beneath the surface; and, moreover, that this increase will be the more rapid, the more nearly the fluidity of the mass approaches that limit at which this process of cooling would cease, and that by conduction begin, since the rapidity of circulation would constantly diminish as the fluidity should approximate to that limit. But still, even in this limiting case, it seems probable that the tendency to produce an equality of temperature throughout the mass will be much greater, and consequently the rate of increase of temperature in approaching the centre much less, than if the cooling of the mass had proceeded by conduction during the same time, the conductive power being very small.

1891 ◽  
Vol 8 (10) ◽  
pp. 456-458 ◽  
Author(s):  
A. J. Jukes-Browne

Until recently no outcrop of the Vectian or Lower Greensand was known to occur between Lulworth on the coast of Dorset and the neighbourhood of Devizes in Wiltshire. It was supposed that, with the exception of a small area of Wealden in the Vale of Wardour, the whole of the Lower Cretaceous Series in Dorset and South Wilts was concealed and buried beneath the overlapping Upper Cretaceous strata. A recent examination of this district however has revealed two areas where the Vectian sands emerge from beneath the Gault. One of these has already been indicated in the pages of the Geological Magazine; the other is the subject of the present communication.


1893 ◽  
Vol 10 (6) ◽  
pp. 251-254
Author(s):  
Arthur H. Foord ◽  
G. C. Crick

The specimen which forms the subject of the present communication was obtained by one of the writers from the Carboniferous Limestone, near Dublin. Although one side of the specimen is covered by matrix, yet the other side and the periphery are so splendidly preserved, and the shell has not been distorted during fossilisation, that the characters of the fossil can be accurately determined (see Woodcut, p. 254).


1902 ◽  
Vol 69 (451-458) ◽  
pp. 485-494 ◽  

The peculiar and apparently hitherto undescribed structures which form the subject of the present communication, were first discovered in the course of an as yet unfinished investigation of the parietal organs in the New Zealand Lamprey ( Geotria australis ). The Ammocœte of this interesting species is known to us only through two specimens: one of these was briefly described by Kner in 1869; the other was for many years in the Museum of the Otago University, Dunedin, and was forwarded to me for investigation by the present curator, Professor W. B. Benham, D. Sc., to whom I desire to express my indebtedness for his great kindness. The specimen which I have thus had the opportunity of investigating was labelled in the handwriting of the late Professor T. J. Parker, F. R. S.—“Ammocœtes stage of Geotria—Opoho Creek.


1833 ◽  
Vol 123 ◽  
pp. 523-544 ◽  

The present communication may be viewed as the continuation of an Essay on the Composition of the Chloride of Barium, which was honoured with a place in the Philosophical Transactions for the year 1829. In resuming the subject after such a long interval, I feel it right to apologize to the Society for the unfinished state in which that Essay has hitherto been left,—an omission far from voluntary, and entirely due to circumstances not subject to my own controul. In one point of view, however, the delay has been advantageous: it has afforded an opportunity to chemists to verify or correct the results contained in my first Essay, and has enabled me to repeat and extend my researches. The object which I proposed to myself in commencing the present inquiry, was to re-examine some of those estimates which chemists have occasion to use continually as elements in their calculations, and to confide in as the foundation of their doctrines. With this view I undertook to determine the relative accuracy of the atomic weights which the British and Continental chemists respectively employ; and several circumstances induced me to begin by analysing the chloride of barium. Dr. Thomson, on whose experiments the British chemists relied, had obtained so many of his results by means of the chloride of barium, that any material error in the constitution of that compound would necessarily vitiate a large part of his table of equivalents; and if, on the other hand, the estimate of Dr. Thomson proved to be correct, an important error would be chargeable against Berzelius, whose numbers are very generally adopted on the Continent. The result of the inquiry is now well known: the source of fallacy, pointed out in my first communication, has been admitted by Dr. Thomson in the new edition of his System of Chemistry, and he has accordingly changed the equivalent of barium from 70 to 68. The inevitable consequence of this change must be apparent to every one who is acquainted with the method of analysis so frequently resorted to by Dr. Thomson. Many of the experiments described in his First Principles of Chemistry are now at irreconcilable variance with each other, and, if relied upon at all, subvert the conclusions which they once appeared to establish. Nor can those parts of his work which are not subject to this criticism be safely applied to the purposes of science. His view, for instance, of the composition of the compounds of oxygen with phosphorus, arsenic, and antimony, has been lately abandoned by himself; and in the course of the present Essay I shall have occasion to prove, that the atomic weights which he has employed for silver and chlorine are likewise inadmissible. His analysis of sulphate of zinc, which was made, to use Dr. Thomson’s own words, “the foundation on which he endeavoured to rear the whole subsequent doctrine of the atomic weight of bodies,” is peculiarly objectionable. Besides being vitiated by his error in the equivalent of barium, the oxide of zinc was determined by a method which involved an error in principle, and was in practice so complex as to be unfit for the extremely important object which it was intended to serve.


1877 ◽  
Vol 25 (171-178) ◽  
pp. 553-559 ◽  

In two papers by one of the authors of the present communication, which appeared in the Philosophical Magazine for March and April 1876, it has been shown that the motion of the blackened disks of a Crookes's radiometer can be explained by the known dynamical properties of the trace of gas which is present, and the term “ Crookes s force is pioposed to designate the reaction which comes into play between the blackened disks and the walls of the exhausted chamber when a difference of temperature exists between them. Shortly after the first of these papers appeared we commenced an experimental investigation of the subject with the view of learning, if possible, the laws to which the force conforms. The investigation is still in progress, and, being ex­ceedingly tedious, it will require a great expenditure of time before it is completed; we propose, however, in this preliminary paper to describe the apparatus and methods of observation employed, and to give some of the results already obtained. If the pressure which is exerted on the blackened pith surfaces reacts on the sides of the glass envelope, it follows that a transparent disk delicately suspended close to a stationary disk of blackened pith ought to move away from the pith, and therefore towards the light, when the pith is illuminated. This inference was submitted to the test of ex­periment by means of an apparatus represented in fig. 1 and constructed as follows :—A piece of elder-pith 2·5 centims. in length and 1·2 centim. in breadth, blackened on one side, was fastened by one end to the interior surface of the bulb of an ordinary boiling-flask (of about 200 cub. centims. capacity) in such a manner that the free end of the pith extended towards the middle of the bulb. A light glass rod with a small magnet on one end, and a disk of thin microscope-glass on the other end, was so suspended in the bulb that the glass disk could be readily balanced in a position nearly parallel with the surface of the blackened pith, and a few millims. distant from it. The silk fibre from which the glass rod was sus­pended hung from a fixed arm at the upper end of a tube, the lower end of which was hermetically fastened into the neck of the flask. An elongation of this tube (not shown in the figure) with a contraction for sealing, served to connect the apparatus with the exhaust-tube of a Sprengel pump. The pump was set in action, and occasionally the flame of an ordinary gas-burner was held at a distance of about 10 centims. from the blackened pith, while the microscope-glass was closely watched. When the gauge of the pump showed a tension of 7 millims., as com­pared with the mercurial column of a barometer standing in the same vessel of mercury, the glass disk was distinctly repelled from the pith and towards the source of light. As the exhaustion was continued the repulsion between the pith and the glass increased. The apparatus was sealed off from the pump when the mercury falling in the exhaust tube had for some days produced a metallic sound. Feeble illumination now caused the glass disk to be forcibly driven away from the pith.


Author(s):  
S.R. Allegra

The respective roles of the ribo somes, endoplasmic reticulum, Golgi apparatus and perhaps nucleus in the synthesis and maturation of melanosomes is still the subject of some controversy. While the early melanosomes (premelanosomes) have been frequently demonstrated to originate as Golgi vesicles, it is undeniable that these structures can be formed in cells in which Golgi system is not found. This report was prompted by the findings in an essentially amelanotic human cellular blue nevus (melanocytoma) of two distinct lines of melanocytes one of which was devoid of any trace of Golgi apparatus while the other had normal complement of this organelle.


2010 ◽  
Vol 4 (2) ◽  
pp. 135-156 ◽  
Author(s):  
Dorothea E. Schulz

Starting with the controversial esoteric employment of audio recordings by followers of the charismatic Muslim preacher Sharif Haidara in Mali, the article explores the dynamics emerging at the interface of different technologies and techniques employed by those engaging the realm of the Divine. I focus attention on the “border zone” between, on the one hand, techniques for appropriating scriptures based on long-standing religious conventions, and, on the other, audio recording technologies, whose adoption not yet established authoritative and standardized forms of practice, thereby generating insecurities and becoming the subject of heated debate. I argue that “recyclage” aptly describes the dynamics of this “border zone” because it captures the ways conventional techniques of accessing the Divine are reassessed and reemployed, by integrating new materials and rituals. Historically, appropriations of the Qur’an for esoteric purposes have been widespread in Muslim West Africa. These esoteric appropriations are at the basis of the considerable continuities, overlaps and crossovers, between scripture-related esoteric practices on one side, and the treatment by Sharif Haidara’s followers of audio taped sermons as vessels of his spiritual power, on the other.


Author(s):  
Iryna Rusnak

The author of the article analyses the problem of the female emancipation in the little-known feuilleton “Amazonia: A Very Inept Story” (1924) by Mykola Chirsky. The author determines the genre affiliation of the work and examines its compositional structure. Three parts are distinguished in the architectonics of associative feuilleton: associative conception; deployment of a “small” topic; conclusion. The author of the article clarifies the role of intertextual elements and the method of constantly switching the tone from serious to comic to reveal the thematic direction of the work. Mykola Chirsky’s interest in the problem of female emancipation is corresponded to the general mood of the era. The subject of ridicule in provocative feuilleton is the woman’s radical metamorphoses, since repulsive manifestations of emancipation becomes commonplace. At the same time, the writer shows respect for the woman, appreciates her femininity, internal and external beauty, personality. He associates the positive in women with the functions of a faithful wife, a caring mother, and a skilled housewife. In feuilleton, the writer does not bypass the problem of the modern man role in a family, but analyses the value and moral and ethical guidelines of his character. The husband’s bad habits receive a caricatured interpretation in the strange behaviour of relatives. On the one hand, the writer does not perceive the extremes brought by female emancipation, and on the other, he mercilessly criticises the male “virtues” of contemporaries far from the standard. The artistic heritage of Mykola Chirsky remains little studied. The urgent task of modern literary studies is the introduction of Mykola Chirsky’s unknown works into the scientific circulation and their thorough scientific understanding.


Author(s):  
Maxim B. Demchenko ◽  

The sphere of the unknown, supernatural and miraculous is one of the most popular subjects for everyday discussions in Ayodhya – the last of the provinces of the Mughal Empire, which entered the British Raj in 1859, and in the distant past – the space of many legendary and mythological events. Mostly they concern encounters with inhabitants of the “other world” – spirits, ghosts, jinns as well as miraculous healings following magic rituals or meetings with the so-called saints of different religions (Hindu sadhus, Sufi dervishes),with incomprehensible and frightening natural phenomena. According to the author’s observations ideas of the unknown in Avadh are codified and structured in Avadh better than in other parts of India. Local people can clearly define if they witness a bhut or a jinn and whether the disease is caused by some witchcraft or other reasons. Perhaps that is due to the presence in the holy town of a persistent tradition of katha, the public presentation of plots from the Ramayana epic in both the narrative and poetic as well as performative forms. But are the events and phenomena in question a miracle for the Avadhvasis, residents of Ayodhya and its environs, or are they so commonplace that they do not surprise or fascinate? That exactly is the subject of the essay, written on the basis of materials collected by the author in Ayodhya during the period of 2010 – 2019. The author would like to express his appreciation to Mr. Alok Sharma (Faizabad) for his advice and cooperation.


2019 ◽  
Vol 95 (2) ◽  
pp. 231-245
Author(s):  
Erik Ode

Abstract De-Finition. Poststructuralist Objections to the Limitation of the Other The metaphysic tradition always tried to structure the world by definitions and scientific terms. Since poststructuralist authors like Derrida, Foucault and Deleuze have claimed the ›death of the subject‹ educational research cannot ignore the critical objections to its own methods. Definitions and identifications may be a violation of the other’s right to stay different and undefined. This article tries to discuss the scientific limitations of the other in a pedagogical, ethical and political perspective.


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