scholarly journals Bakerian lecture.—Further experiments on the action exerted by certain metals and other bodies on a photographic plate

1898 ◽  
Vol 63 (389-400) ◽  
pp. 102-112 ◽  
Keyword(s):  
Experimental Evidence ◽  
Photographic Plate ◽  
General Character ◽  
Ordinary Light ◽  
Other Substances ◽  
Printing Ink

In a paper read before this Society in June last it was state that certain metals, alloys, and other substances such as picture copal, printing ink, straw board, &c., were able to act even at distance on a sensitive photographic plate, producing effects simila in appearance and developed in the same way as plates which had been acted on by ordinary light. At that time sufficient experimental evidence had not been obtained to determine the nature of this action, or even to clearly indicate its general character, whether in fact the action arose from vapour given off by the active body or whether phosphorescence was produced which acted on the plate.

scholarly journals The photographic action of β-rays

1927 ◽  
Vol 114 (767) ◽  
pp. 266-276 ◽  
Keyword(s):  
Direct Method ◽  
Photographic Plate ◽  
Characteristic Curve ◽  
Total Charge ◽  
X Rays ◽  
Reciprocity Law ◽  
Ordinary Light ◽  
General Experience ◽  
High Degree ◽  
The Relationship

The study of β-ray spectra has now advanced to that stage at which, for the majority of radioactive substances, the velocities of the homogeneous electrons forming the “lines” have been measured with a fair accuracy. The relative intensities of the “lines” have in the past been obtained by visual estimation of the photographic blackening of the plates on which they have been recorded, and it has become important to obtain more precise information on this subject. The most direct method of determining the relative intensities would be to count the number of, or measure the total charge carried by, the particles forming the lines. This is not practicable, to any high degree of accuracy, because of the small effects which are obtainable, and it is obvious that the photographic plate, in giving quite intense and sharp lines, in addition to a permanent record, presents many advantages. The use of this method, however, necessitates the calibration of the plate both for the variation of the blackening with exposure and also with velocity of the rays. The corresponding calibrations for ordinary light have now become a matter of routine, but since there has, as yet, been little systematic work on the behaviour of the photographic plate to β-rays, we have thought it best to record in this paper such experiments as we have found necessary before undertaking the main intensity problem. It is the dependence of blackening on exposure which is mainly treated in this paper, although we have in addition obtained some interesting results on the effect of β-particles of different velocities. In an investigation on the relationship between blackening and exposure i. e ., the characteristic curve of a type of plate, it is first necessary to find the dependence of the blackening D on the time of exposure t , when the product of intensity I and time of exposure t is kept constant. If D is independent of t , when I. t is constant, then the Reciprocity Law of Bunsen and Roscoe is said to be valid for the plate. This law, although it has to be slightly modified for luminous radiation, has been shown to be true in the case of X-rays and also for heterogeneous β-rays. In all previous work on the photographic action of β-rays the particles were of heterogeneous velocities, but in view of the ultimate object of this investigation it was thought unsatisfactory to employ heterogeneous particles, and although the procedure was thereby made rather more laborious, beams of practically homogeneous particles, taken from the continuous β-ray spectrum, were used. It is in general important, when dealing with an unknown type of plate, after investigating the validity of the Reciprocity Law, to determine the variation of the characteristic curve with time of development, and thereby find the optimum value. Our general experience in photographing β-ray spectra had led us to employ a particular type of plate and method of development, and the main value of our experiments on the variation of the characteristic curve with time of development was that it indicated the error introduced into the value of the density for a given uncertainty in the time of development.

scholarly journals Papers read to the Society, June 17, 1897

1897 ◽  
Vol 61 (369-377) ◽  
pp. 396-398
Keyword(s):  
Photographic Plate ◽  
Physical Structure ◽  
Body Cavity ◽  
The Body ◽  
Pure Gold ◽  
Frequency Variation ◽  
Other Substances ◽  
University College London ◽  
Lord Kelvin ◽  
The University

I. “An Experimental Research upon Cerebro-cortical Afferent and Efferent Tracts.” By David Ferrier, M.D., F. R. S., Professor of Neuropathology, and William Aldren Turner, M.D.., F.R.C.P., Demonstrator of Neuropathology, King’s College, London. II. “On the Relative Behaviour of the H and K Lines of the Spectrum of Calcium.” By William Huggins, D.C.L., LL.D., F. R. S., and Mrs. Huggins. III. “ Further Observations of Enhanced Lines.” By J. Norman Lockyer, C.B., F. R. S. IV. “The Total Solar Eclipse of August 9, 1896. Report on the Expedition to Kiö Island.” By J. Norman Lockyer, C.B., F. R. S. V. “On the Classification of Stars of the δ Cephei Class.” By J. Norman Lockyer, C.B., F. R. S. VI. “On the Appearance of the Cleveite and other New Gas Lines in the Hottest Stars.” By J. Norman Lockyer, C.B., F. R. S. VII. “On the Action exerted by certain Metals and other Substances on a Photographic Plate.” By W. J. Russell, Ph.D., F. R. S., Lecturer on Chemistry at St. Bartholomew’s Hospital. VIII. “Stress and other Effects produced in Resin and in a Viscid Compound of Resin and Oil by Electrification.” By J. W . Swan, F. R. S. IX. On Lunar and Solar Periodicities of Earthquakes.” By Arthur Schuster, F. R. S. X. “Cathode Rays and some analogous Rays.” By Silvanus P. Thompson, D.Sc., F. R. S. XI. “Micro-physical Structure of pure Gold and Micro-segregation in Gold Alloys.” By Thomas Andrews, F. R. S. XII. “A Maya Calendar Inscription, interpreted by Goodman’s Tables.” By Alfred P. Maudslay. Communicated by F. Ducane Godman, F. R. S. XIII. “Studies in the Morphology of Spore-producing Members Part III. Marattiaceæ.” By F. O. Bower, Sc.D., F. R. S., Regius Professor of Botany in the University of Glasgow. XIV. “The Vector Properties of Alternating Currents and other Periodic Quantities.” By W. E. Sumpner, D.Sc. Communicated by O. Henrici, F. R. S. XV. “On the Theory of the Magneto-Optic Phenomena of Iron, Nickel, and Cobalt.” By J. G. Leathem, B.A., Fellow of St. John’s College, Cambridge. Communicated by Sir Robert S. Ball, F. R. S. XVI. “Some Observations on the Chemistry of the Contents of the Alimentary Tract under various conditions ; and on the Influence of the Bacteria present in them.” By A. Lockhart Gillespie, M.D., F.R.C.P.(Ed), F. R. S. E - Communicated by Professor J. G. McK endrick, F. R. S. XVII. “On a Discontinuous Variation occurring in Biscutella lævigata." By Miss E. R. Saunders, Lecturer at Newnham College, Cambridge. Communicated by W. Bateson, F. R. S. XVIII. “Magnetic Properties of Iron at High Temperatures.” By J. Hopkinson, D.Sc., F. R. S. XIX. “On the Change of Absorption produced by Fluorescence.” By John Burke, B.A.(Dub.), Berkeley Fellow of the Owens College, Manchester. Communicated by Professor Arthur Schuster, F. R. S. XX. “Influence of Acids and Alkalis upon the Electrotonic Currents of Medullated Nerve.” By Augustus W. Waller, M.D., F. R. S. XXI. “On the Distribution of Frequency (Variation and Correlation) of the Barometric Height at diverse Stations.” By Karl Pearson, M.A., F. R. S., University College, London, and Miss Alice Lee, Bedford College. XXII. “On the Openings in the Wall of the Body-cavity of Vertebrates.” By E. J. Bles. Communicated by Dr. Hans Gadow, F. R. S. XXIII. “Electrification of Air, of Vapour of Water, and of other Gases.” By Lord Kelvin, G.C.V.O., F. R. S., Magnus Maclean, D.Se., F.R.S.E., and Alexander Galt, B„Sc., F.R.S.E. XXIV. “Note on recent Investigations on the Mechanical Equivalent of Heat.” By E. H. Griffiths, M.A., F. R. S.

On the action exerted by certain metals and other substances on a photographic plate

1897 ◽  
Vol 61 (369-377) ◽  
pp. 424-433 ◽  
Keyword(s):  
Photographic Plate ◽  
Uranium Compounds ◽  
Spectroscopic Examination ◽  
Other Substances

Having some years ago prepared for the purpose of spectroscopic examination several uranium compounds, it was of interest to make further use of them by repeating some of the very important experiments which Becquerel has made with these compounds. He has shown that if the metal or some of its salts be placed on a photographic plate in perfect darkness, and allowed to remain there for some days, the plate becomes acted on, the action being rendered evident by the ordinary photographic process of development. This action is readily produced, and belongs apparently to all the salts of this metal, and, as Becquerel has shown, to uranous as well as uranic salts.

scholarly journals PREPARATION OF COLLODION SACS FOR USE IN BACTERIOLOGY

1921 ◽  
Vol 33 (1) ◽  
pp. 25-43 ◽  
Author(s):  
Frederick L. Gates
Keyword(s):  
Sodium Chloride ◽  
Alcohol Treatment ◽  
General Character ◽  
High Permeability ◽  
Factors Influencing ◽  
Large Numbers ◽  
Other Substances ◽  
Standardized Method

A standardized method is described in detail by which collodion sacs suitable for intraperitoneal incubation and for other bacteriological experiments may be produced in large numbers, sterilized, and handled with convenience and the minimum danger of contamination. Various factors influencing permeability have been subjected to experiment. Like Brown, we found that immersion in alcohol is the most important factor, but the high permeability conferred by alcohol treatment is lost during heat sterilization if the membrane was previously allowed to dry. Quantitative experiments on the dialysis of sodium chloride, and simple tests with other substances indicate the general character of the membranes and their probable field of usefulness in bacteriology.

scholarly journals III.—Notes on the composition of Clays, Slates, etc., And on some points in their Contact-Metamorphism

1894 ◽  
Vol 1 (2) ◽  
pp. 64-75
Author(s):  
W. Maynard Hutchings
Keyword(s):  
Polarized Light ◽  
White Mica ◽  
The Other ◽  
Contact Metamorphism ◽  
Stages Of Development ◽  
Characteristic Appearance ◽  
Definite Form ◽  
Yellow Substance ◽  
Ordinary Light ◽  
Other Substances

After this substance has been well observed in good occurrences, it is always recognized at once, even as isolated small patches in a slide. It has a very characteristic appearance among the other constituents. It is marked off, for instance, by its special refraction from anything else that occurs in these rocks, and has other characteristics not to be missed when once observed, but not very easy to exactly describe. As soon as it ceases to be quite inert in polarized light, as soon as the speckly polarization sets in, it has also a more or less granular appearance in ordinary light with lowered condenser, which is very characteristic.indifferent slides, and often in one and the same slide, various stages of development may be observed in it from the first speckled appearance in polarized light up to a point where flakelets of white mica are recognized as forminginit, lying “criss-cross”inall directions. It passes in this way in some cases almost wholly into mica, with apparently other substances which cannot be identified with certainty, the transition, and connection with the original substance, being all the time distinct and beyond mistake.In the inner zones, the “hornfels-zones,“ this substance is usually present in smaller amount, as already stated; but examples of its abundant occurrence are not wanting, as for instance in a hornfels from Spitzenberg, in the Harz. There is a mosaic of quartz and felspar, with brown mica and some white mica. The yellow substance lies in amongst, and surrounds, the minerals of this mosaic. It has no definite form of its own, simply occupying spaces and taking the outlines of the other minerals. It is all either in the minutely-speckly stage or variously developed from this upwards to mica; and the impression made is that if it had all developed as far as some portions of it have done, the whole mosaic-grains of the slides would be mixed in with and surrounded by white mica, as may not infrequently be observed in these contact-rocks.

How do memory modules differentially contribute to familiarity and recollection?

2019 ◽  
Vol 42 ◽  
Author(s):  
Olya Hakobyan ◽  
Sen Cheng
Keyword(s):  
Recognition Memory ◽  
Experimental Evidence ◽  
Subjective Experience ◽  
Target Article ◽  
Memory Modules ◽  
Familiarity And Recollection ◽  
Memory Contents

Abstract We fully support dissociating the subjective experience from the memory contents in recognition memory, as Bastin et al. posit in the target article. However, having two generic memory modules with qualitatively different functions is not mandatory and is in fact inconsistent with experimental evidence. We propose that quantitative differences in the properties of the memory modules can account for the apparent dissociation of recollection and familiarity along anatomical lines.

Redox Reactions in Lipid Membranes as a Model for Primordial Energy-Conserving Systems

1997 ◽  
Vol 161 ◽  
pp. 437-442
Author(s):  
Salvatore Di Bernardo ◽  
Romana Fato ◽  
Giorgio Lenaz
Keyword(s):  
Experimental Evidence ◽  
Lipid Membranes ◽  
Energy Supply ◽  
Redox Reactions ◽  
Living Systems ◽  
Asymmetric Distribution ◽  
Conservation Of Energy ◽  
Asymmetrical Distribution ◽  
Energy Conserving ◽  
Living Organisms

AbstractOne of the peculiar aspects of living systems is the production and conservation of energy. This aspect is provided by specialized organelles, such as the mitochondria and chloroplasts, in developed living organisms. In primordial systems lacking specialized enzymatic complexes the energy supply was probably bound to the generation and maintenance of an asymmetric distribution of charged molecules in compartmentalized systems. On the basis of experimental evidence, we suggest that lipophilic quinones were involved in the generation of this asymmetrical distribution of charges through vectorial redox reactions across lipid membranes.

2.2. Working Group 2: Conceptual Definitions of Reference Coordinate Systems for Earth Dynamics

1975 ◽  
Vol 26 ◽  
pp. 21-26
Keyword(s):  
Coordinate System ◽  
Working Group ◽  
General Character ◽  
Coordinate Systems ◽  
Reference Coordinate System ◽  
Group 2 ◽  
Definition Of ◽  
Earth Dynamics

An ideal definition of a reference coordinate system should meet the following general requirements:1. It should be as conceptually simple as possible, so its philosophy is well understood by the users.2. It should imply as few physical assumptions as possible. Wherever they are necessary, such assumptions should be of a very general character and, in particular, they should not be dependent upon astronomical and geophysical detailed theories.3. It should suggest a materialization that is dynamically stable and is accessible to observations with the required accuracy.

Results of Latitude Observations with the Floating Zenith Telescope at Mizusawa: Comparisons between the Results Obtained from the Astronomical and Doppler Satellite Observations

1975 ◽  
Vol 26 ◽  
pp. 461-468
Author(s):  
S. Takagi
Keyword(s):  
Photographic Plate ◽  
Satellite Observations ◽  
Pole Motion

In this article, we intended to see whether we can obtain the same pole motion from two kinds of telescopes: the floating zenith telescope (PZT) and the ILS zenith telescope (VZT). The observations with the PZT have been pursued since 1967.0 with a star list whose star places are taken from the PK4 and its supplement. We revised the method of reduction of the observations with the PZT by adopting a variable scale value for the photographic plate (Takagi et al., 1974).

Electron Channeling Patterns

1977 ◽  
Vol 35 ◽  
pp. 12-13
Author(s):  
David C. Joy
Keyword(s):  
Electron Diffraction ◽  
Incidence Angle ◽  
Photographic Plate ◽  
Diffraction Effect ◽  
Angle Of Incidence ◽  
Bulk Single Crystal ◽  
Time Resolved ◽  
Electron Channeling ◽  
Spatially Resolved ◽  
Large Bulk

Electron channeling patterns (ECP) were first found by Coates (1967) while observing a large bulk, single crystal of silicon in a scanning electron microscope. The geometric pattern visible was shown to be produced as a result of the changes in the angle of incidence, between the beam and the specimen surface normal, which occur when the sample is examined at low magnification (Booker, Shaw, Whelan and Hirsch 1967).A conventional electron diffraction pattern consists of an angularly resolved intensity distribution in space which may be directly viewed on a fluorescent screen or recorded on a photographic plate. An ECP, on the other hand, is produced as the result of changes in the signal collected by a suitable electron detector as the incidence angle is varied. If an integrating detector is used, or if the beam traverses the surface at a fixed angle, then no channeling contrast will be observed. The ECP is thus a time resolved electron diffraction effect. It can therefore be related to spatially resolved diffraction phenomena by an application of the concepts of reciprocity (Cowley 1969).

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