scholarly journals On an artificial substance resembling shell; by Leonard Horner, Esq. F. R. S. L. and Ed.: with an account of the examination of the same; by Sir David Brewster, K. H., LL. D

1837 ◽  
Vol 3 ◽  
pp. 375-377
Keyword(s):  
Optical Properties ◽  
Chemical Analysis ◽  
Polished Surface ◽  
Double Refraction ◽  
External Appearance ◽  
Mechanical Structure ◽  
Brown Colour ◽  
Lime Water ◽  
Foliated Structure

The author, having noticed a singular incrustation on both the internal and external surfaces of a wooden dash-wheel, used in bleaching, at the Cotton Factory of Messrs. J. Finlay and Co., at Catrine, in Ayrshire, instituted a minute examination of the properties and composition of this new substance. He describes it as being compact in its texture, of a brown colour, and highly polished surface, with a metallic lustre, and presenting in some parts a beautiful iridescent appearance: when broken, it exhibits a foliated structure. Its obvious resemblance, in all these respects, to many kinds of shell, led the author to inquire into its intimate mechanical structure, and into the circumstances of its formation. He found, by chemical analysis, that it was composed of precisely the same ingredients as shell; namely, carbonate of lime and animal matter. The presence of the former was easily accounted for; as the cotton cloths which are placed in the compartments of the wheel, in order that they may be thoroughly cleansed by being dashed against its sides, during its rapid revolutions, have been previously steeped and boiled in lime water. But it was more difficult to ascertain the source of the animal matter; this, however, was at length traced to the small portion of glue, which, in the factory where the cloth had been manufactured, was employed as an ingredient in forming the paste, or dressing, used to smooth and stiffen the warp before it is put into the loom. These two materials, namely lime and gelatine, being present in the water in a state of extreme division, are deposited very slowly by evaporation; and thus compose a substance which has a remarkable analogy to shell, not only in external appearance, and even pearly lustre, but also in its internal foliated structure, and which likewise exhibits the same optical properties with respect to double refraction and polarizing powers.

Sector growth and symmetry of (F,OH) apatite from the Asio mine, Japan

1994 ◽  
Vol 58 (391) ◽  
pp. 307-314 ◽  
Author(s):  
Mizuhiko Akizuki ◽  
Hirotugu Nisidoh ◽  
Yasuhiro Kudoh ◽  
Tomohiro Watanabe ◽  
Kazuo Kurata
Keyword(s):  
Optical Properties ◽  
Crystal Growth ◽  
Electron Diffraction ◽  
Chemical Analysis ◽  
Growth Surface ◽  
Complete Disappearance ◽  
X Ray ◽  
Solid Crystal ◽  
Wet Chemical ◽  
Growth Features

AbstractA study of apatite crystals from the Asio mine, Japan, showed sectoral texture related to the growth of the crystal, and with optically biaxial properties within the sectors. Wet chemical analysis gave a composition Ca5(PO4)3(F0.64,OH0.38,Cl0.01)1.03 for the specimen.Additional diffraction spots were not observed in precession and oscillation X-ray photographs and electron diffraction photographs. Since the internal textures correlate with the surface growth features, it is suggested that the internal textures and the unusual optical properties were produced during nonequilibrium crystal growth. The fluorine/hydroxyl sites in hexagonal apatite are symmetrically equivalent in the solid crystal but, at a growth surface, this equivalence may be lost, resulting in a reduction of crystal symmetry. Heating of the apatite to about 850°C results in the almost complete disappearance of the optical anomalies due to disordering, which may be related to the loss of hydroxyl from the crystal.

RESEARCH ON THE BOTANICAL AND PHARMACOGNOSTIC PARTICULARITIES OF THE INDIGENOUS SPECIES LYSIMACHIA NUMMULARIA L.

2021 ◽  
Author(s):  
Suciu Felicia ◽  
Arcuș Mariana ◽  
Roșca Adrian Cosmin ◽  
Bucur Laura ◽  
Popescu Antoanela ◽  
...  
Keyword(s):  
Chemical Analysis ◽  
Native Species ◽  
Reproductive Organs ◽  
Indigenous Species ◽  
External Appearance ◽  
Vegetative Organs ◽  
Naked Eye ◽  
Hydrophilic Nature ◽  
Macroscopic Examination

"Preliminary pharmacochemical research on Lysimachia nummularia L. was performed by dint of pharmacognostic analysis (macroscopic examination, global chemical analysis, preliminary quantitative determinations).The article includes the analysis of the macroscopic characters of the vegetative organs (root, stem and leaf), as well as of the reproductive organs (flower, fruit, seed) belonging to the spontaneous native species Lysimachia nummularia L. Morphological features were described and discussed. The identification of these aspects was done with the naked eye, but also with the help of a hand magnifier and a binocular magnifier. The results revealed that the external appearance of the plant justifies the species belonging to the genus Lysimachia, family Primulaceae. They are found in the glabrous and creeping appearance of the plant, opposite, almost round leaves, solitary, yellow flowers, axillary with vigorous pedicels, perianth pentamer, actinomorphic, dialisepal and dialipetal, globular capsule fruit. The semi-hydrophilic nature is found in the presence of adventitious roots that develop both from the rhizome and at the nodes of the stem. The preliminary quantitative determinations performed were loss by drying as well as soluble substances of the species Lysimachia nummularia L. Following the global chemical analysis, active principles known in the literature for the antioxidant potential were identified. Following the preliminary quantitative determinations (drying loss, determination of soluble substances) results comparable to those in the literature on the content of volatile substances and soluble substances were obtained."

An optical and X-ray examination of the basic-slag mineral silicocarnotite

1949 ◽  
Vol 28 (204) ◽  
pp. 496-504 ◽  
Author(s):  
D. P. Riley ◽  
E. R. Segnit
Keyword(s):  
Optical Properties ◽  
Chemical Analysis ◽  
Basic Slag ◽  
X Ray

Blue pleochroic crystals obtained from basic slag were first described by Carnot and Richard. They published a chemical analysis, some of the optical properties, and a brief description of the forms they observed. The crystals were stated to be orthorhombic, with a composition of 5CaO.P205.SiO2. Several authors later described similar crystals. None, however, gave a thorough account of the optical properties. These various papers were summarized and discussed by Kroll, who accepted Carnot's formula, but concluded, from Bücking and Linck's examination, that the material was monoclinic. Kroll applied the rather unfortunate term ‘silico-carnotite’ to these crystals.The present work shows that silicocarnotite occurs in only one modification–orthorhombic. The crystals drawn by Bricking and Linck and described as monoclinic are, in fact, identical with our orthorhombie crystals.

Xonotlite and rodingites from Wairere, New Zealand

1973 ◽  
Vol 39 (302) ◽  
pp. 233-240 ◽  
Author(s):  
J. P. O'Brien ◽  
K. A. Rodgers
Keyword(s):  
Optical Properties ◽  
New Zealand ◽  
Chemical Analysis ◽  
Metasomatic Process

SummaryXenoliths of eucritic gabbros in an alpine-serpentinite body at Wairere have been altered to rodingites and xonotlite about their margins by hydrothermal metasomatism at temperatures between 430–470°C A chemical analysis and the optical properties of the xonotlite are reported, the textures of the rocks are described, and the metasomatic process is discussed.

On the laws of polarization and double refraction in regularly crystal­lized bodies. By David Brewster, LL. D. F. R. S. and Edin. In a letter to the Right Hon. Sir Joseph Banks, Bart. G. C. B. P. R. S

1833 ◽  
Vol 2 ◽  
pp. 92-93
Keyword(s):  
Optical Properties ◽  
General Principle ◽  
General View ◽  
Double Refraction ◽  
Primitive Form ◽  
General Law ◽  
Combined Action ◽  
The Right ◽  
Polarization Of Light ◽  
High Degree

In the different inquiries which the author has already laid before this Society, his attention was often directed to the phenomena of regular crystals; but he only lately succeeded in reducing under a general principle all those complex appearances which result from the combined action of more than one axis of double refraction. In this paper Dr. Brewster gives a general view of the present state of our knowledge respecting the double refraction and polarization of light, and afterwards traces the steps which led him to the discovery of the general law. He began his researches by the examination of 165 crystals, in 145 of which he discovered the property of double refraction. In 80 he was able to ascertain whether they had one or more axes; and by examining the tints which they exhibited at va­rious angular distances from the axes, whence the forces emanate, he has been led to a general principle, which embraces all the phenomena and extends to the most complex as well as to the most simple de­velopment of the polarizing forces. This general principle, says Dr. Brewster, is in no respect an empyrical expression of the facts which it represents, nor is it supported by any empyrical data. Founded on the principles of mechanics, it is a law rigorously physical, by which we are enabled to calculate all the tints of the coloured rings, and all the phenomena of double refraction, with as much accuracy as we can compute the motions of the heavenly bodies. The faculty of depolarization, explained by the author in a former paper, has been considered as sufficient indication of two separate images; and upon this principle it has been stated that all crystals are doubly refractive whose primitive form is neither the cube nor the regular octohedron: but this is incorrect; for some of these crystals possess a doubly refracting structure in a high degree. Ad­mitting the statement, however, it could not have been used as a rule for determining whether a crystal refracts doubly or singly; for it is more difficult to detect the primitive form than to examine the optical properties. Tungstate of lime, for instance, would have been reckoned a crystal without double refraction, when Haüy believed its primitive form to be the cube, although it is highly doubly refractive.

scholarly journals VIII. On the Optical Properties of Muriate of Soda, Fluate of Lime, and the Diamond, as exhibited in their action upon Polarised Light

1818 ◽  
Vol 8 (1) ◽  
pp. 157-164 ◽  
Author(s):  
David Brewster
Keyword(s):  
Optical Properties ◽  
Double Refraction ◽  
Polarised Light

It has long ago been remarked by the Abbé Hauy, that the property of Double Refraction is not possessed by any of those crystals the form of whose integrant molecule is distinguished by its symmetry, such as the Cube and the Regular Tetraedron. This class of minerals comprehends Fluate of Lime, Muriate of Soda, Spinelle Ruby, Muriate of Ammonia, Alum and the Diamond; and though M. Hauy had examined only a very small number of doubly refracting crystals, yet, with the exception of the Diamond, which I have found in many cases to possess the property of Double Refraction, his remark was confirmed by the experiments of Malus, Biot and myself, who considered all the crystals of this class as exercising no more action upon polarised light than a mass of water.

scholarly journals III. Experiments on the depolarisation of light as exhibited by various mineral, animal, and vegetable bodies, with a reference of the phenomena to the general principles of polarisation. By David Brewster, LL. D. F. R. S. Edin and F. S. A. Edin. In a letter addressed to the Right Hon. Sir Joseph Banks, Bart. K. B. P. R. S

1815 ◽  
Vol 105 ◽  
pp. 29-53 ◽  
Keyword(s):  
Optical Properties ◽  
General Principle ◽  
Gum Arabic ◽  
Natural Philosopher ◽  
Double Refraction ◽  
Short Account ◽  
Vegetable Products ◽  
Direct Experiment ◽  
The Right ◽  
Iceland Spar

Dear Sir Towards the end of the year 1812, when I was engaged in examining the light transmitted through diaphanous bodies, I discovered the property which many of them possessed of depolarising the rays of light, or of depriving them of the po­larity which they had received, either by reflection from the surface of a transparent body, or by transmission through a plate of agate. A short account of these experiments, which were exhibited to many of my friends in Edinburgh, was soon afterwards published in my treatise on new philosophical instruments. As this singular property was possessed by numerous sub­stances that exhibited no marks of double refraction, and even by animal and vegetable products, such as horn, tortoise­ shell, and gum Arabic, it appeared necessary to distinguish it by a new name, and to refer it to a species of crystalliza­tion different from that of doubly refracting crystals. The circumstance, however, of agate and Iceland spar possessing the faculty both of polarising and depolarising light, and the constant relation in the position of the axes which regulated these apparently opposite actions, induced me to think that the two classes of phenomena had the same origin. This opinion was afterwards strengthened by an experiment with a bundle of glass plates, in which light was depolarised by polarising it in a new plane; but in applying the principle to other phenomena, I was baffled in every attempt to generalise them. By extending, however, and varying the experiments; by examining the optical properties of every substance which I could command, and by comparing their structure with the phenomena which they exhibited, I have been led to the general principle to which they all belong, and to a series of results which, from their very nature, could not easily have been established by direct experiment. These conclusions, independently of their optical consequences, are peculiarly in­teresting to the chemist and the natural philosopher, by dis­closing the structure of organised substances, and exhibiting new relations among the bodies of the animal, the vegetable, and the mineral kingdoms.

Holtite: a new mineral allied to dumortierite

1971 ◽  
Vol 38 (293) ◽  
pp. 21-25 ◽  
Author(s):  
M. W. Pryce
Keyword(s):  
Optical Properties ◽  
Chemical Analysis ◽  
Western Australia ◽  
Prime Minister ◽  
Unit Cell ◽  
New Mineral ◽  
Space Group ◽  
Free Basis ◽  
X Ray ◽  
The Government

SummaryHoltite, a new mineral allied to dumortierite, occurred as pebbles with stibiotantalite and tantalite on an alluvial tin lease near Greenbushes, Western Australia, and is named after the late H. E. Holt, Prime Minister of Australia.The mineral is orthorhombic with a 11·905 Å, b 20·355 Å, c 4·690 Å, space group Pmcn, weak supercell 2a, 2b, c developed. Crystals are elongated along c, D 3·90 ± 0·02, hardness 8½, fluorescent. Optical properties α 1·743−1·746, mainly yellow, ‖ [001], β 1·756−1·759, colourless, γ 1·758−1·761, colourless, 2Vα 49−55°, r < v. X-ray powder data are given.Chemical analysis gave SiO2 20·30, Sb2O5 4·61, Al2O3 46·43, Ta2O5 11·24, Nb2O5 0·76, Fe2O3 0·27, MnO 0·05, TiO2 0·09, BeO 0·05, B2O3 1·82, Sb2O3 13·89, H2O+ 0·38, H2O− 0·08, sum 99·97%. On a water-free basis the unit cell contains Al24·5Sb2·56‴Ta1·36Sb0·76vNb0·16Fe0·10‴Be0·05Ti0·03Mn0·02B1·40‴Si9·09O66·85. Compared with dumortierite, 4[(A1,Fe)7BSi3O18] or 4 (X11O18), the holtite unit cell contains approximately 4(X10O17).Type material is preserved at the Government Chemical Laboratories, Perth, Western Australia.

The crystal-structure and optical properties of matlockite (PbFCl)

1934 ◽  
Vol 23 (146) ◽  
pp. 587-597 ◽  
Author(s):  
F. A. Bannister
Keyword(s):  
Crystal Structure ◽  
Optical Properties ◽  
Chemical Composition ◽  
Chemical Analysis ◽  
Single Crystal ◽  
British Museum ◽  
Museum Collection ◽  
X Ray ◽  
Fluorine Determination

It has recently been shown by W. Nieuwenkamp that matlockite is identical in chemical composition and crystal-structure with artificial lead fluochloride PbFC1. His conclusion is based upon powder photographs of the two substances and a fluorine determination of a specimen of matlockite from Matlock, Derbyshire. The present work was undertaken primarily to check Nieuwenkamp's interesting results. Access to an exceptionally fine suite of matlockite specimens in the British Museum collection made possible single crystal X-ray measurements, accurate optical determinations, and a new chemical analysis.

Investigations on surface chemical analysis using X-ray photoelectron spectroscopy and optical properties of Dy3+-doped LiNa3P2O7 phosphor

2016 ◽  
Vol 1118 ◽  
pp. 117-123 ◽  
Author(s):  
K. Munirathnam ◽  
G.R. Dillip ◽  
Shivanand Chaurasia ◽  
S.W. Joo ◽  
B. Deva Prasad Raju ◽  
...  
Keyword(s):  
Optical Properties ◽  
Chemical Analysis ◽  
Photoelectron Spectroscopy ◽  
Surface Chemical ◽  
X Ray ◽  
Surface Chemical Analysis
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