2. On Zinc-Methyl

1862 ◽  
Vol 4 ◽  
pp. 315-317
Author(s):  
J. A. Wanklyn
Keyword(s):  
High Temperature ◽  
Specific Gravity ◽  
Boiling Point ◽  
The Body ◽  
Small Glass ◽  
Vapour Density ◽  
Glass Tubes

Considerable difficulties attend the preparation of zinc-methyl. Frankland, who discovered the body, obtained it by heating pure iodide of methyl and zinc enclosed in small glass tubes. Owing to the high temperature at which reaction takes place, much gas is formed; hence the operation must be confined to very small quantities of materials.No determination of the boiling-point, specific gravity, nor yet of the vapour density of zinc-methyl, was made by its discoverer; from which fact may be inferred how small was the product available for investigation.

scholarly journals The constitution of sulphur vapour

1919 ◽  
Vol 95 (672) ◽  
pp. 484-492 ◽  
Keyword(s):  
Boiling Point ◽  
Diatomic Molecules ◽  
Conclusive Evidence ◽  
The Other ◽  
Molecular Formula ◽  
Reduced Pressure ◽  
Vapour Density ◽  
Temperature And Pressure ◽  
Sulphur Vapour

The constitution of sulphur vapour has been studied by many investigators, the method usually employed being based upon the determination of the density. In 1835 Dumas and Mitscherlich found the vapour density at temperatures near the boiling point to be 6∙56, which corresponds closely with the molecular formula S 6 . Deville and Troost carried out determinations at temperatures ranging from 860°C to 1040°C. and obtained the value 2∙23 which is that required by the formula S 2 . More recently Biltz has shown that below 800°C. the density is greater than is required by the formula S 2 , and at 468°C. becomes 7∙8 which corresponds approximately to the formula S 7 , without any constant value being observed between these temperatures. Bleier and Kohn found that when determinations were made under reduced pressure between 192°C. and 310°C. the density of the vapour gradually rose with increase of pressure and slowly but asymptotically approached the value S 8 . Evidence of the existence of molecules containing eight atoms has also been obtained from an examination of solutions of sulphur. Biltz holds that the value obtained by Dumas and Mitscherlich is only of significance for the conditions of temperature and pressure under which it was determined, and affords no evidence of the presence of hexatomic molecules in the vapour. His view is that only octatomic and diatomic molecules have any existence, the former gradually dissociating into the latter as the temperature is raised until about 900° C., the dissociation of the heavier molecules is complete and the vapour is composed entirely of diatomic molecules. Above this temperature no further change appears to occur. Premier, on the other hand, from a study of the curve representing the change of density with change of pressure considers that it is not unlikely that hexatomic and tetratomic molecules are formed as intermediate pro­ducts of the dissociation of the octatomic molecules. Of this, however, the investigation of the vapour density does not afford any conclusive evidence.

scholarly journals XII. Notes of researches on the poly-ammonias. — No. XIV. Diagnosis of diamines

1862 ◽  
Vol 11 ◽  
pp. 278-281
Keyword(s):  
Boiling Point ◽  
Valuable Data ◽  
Vapour Density ◽  
Satisfactory Manner

In former parts of this inquiry I have had repeated opportunities of discussing the features of distinction between the monamines and diamines. I have shown that the study of the genesis and of the transformations of an ammonia, and the observation of its boiling-point supply most valuable data for the elucidation of this question; and that the most reliable inferences may be drawn from the determination of its vapour-density. In continuing my experiments upon this subject, I have been led to the discovery of a class of salts, the formation of which decides the question in an equally satisfactory manner.

XI. Contributions to our knowledge of antimony pentachloride

1887 ◽  
Vol 42 (251-257) ◽  
pp. 379-387
Keyword(s):  
Boiling Point ◽  
Simple Formula ◽  
Fundamental Importance ◽  
Antimony Pentachloride ◽  
Vapour Density

Some months ago we showed that antimony pentachloride can be distilled, undecomposed, under much diminished pressure; our next step was the attempt to determine the vapour-density under similar conditions. The fact that the boiling point of antimony pentachloride lies much lower than that of the trichloride would seem to show that the vapour-density of the pentachloride, as in the case of the trichloride, corresponds to the simpler formula. Nevertheless, on account of the fundamental importance which the establishment of the simple formula SbCl 5 would have for the valence of antimony, it seemed indispensably necessary to make a determination of the vapour-density.

IV. On the coefficient of expansion of a paraffine of high boiling point

1875 ◽  
Vol 23 (156-163) ◽  
pp. 108-116 ◽  
Keyword(s):  
High Temperature ◽  
Boiling Point ◽  
Exact Determination ◽  
High Boiling Point

In the search for a liquid of high boiling-point which could be used for the exact determination of the coefficient of expansion of iodide of silver, and which at the same time should be free from certain objections which apply to the employment of mercury for this purpose, a paraffine of high boiling-point naturally suggested itself. Mr. W. H. Hatcher, to whom I express my acknowledgments, procured for me a specimen of paraffine which was taken from one of the stills at Messrs. Price’s works at a high temperature. With it the following experiments were made.

scholarly journals 3. On the Constitution of the Essential Oil of Cajeput

1862 ◽  
Vol 4 ◽  
pp. 326-327
Author(s):  
Maximilian Schmidl
Keyword(s):  
Essential Oil ◽  
Phosphoric Acid ◽  
Heavy Oil ◽  
Boiling Point ◽  
Lemon Yellow ◽  
Yellow Colour ◽  
Vapour Density

The author shows, that oil of cajeput is a mixture of an oil boiling about 175° Cent., and one or more oils of higher boiling point. In the present paper he investigates the first of those substances. When purified by repeated distillation, it is a colourless, limpid fluid, which by analysis and determination of its vapour density, is shown to have the formula C20 H16 + 2HO. When treated with anhydrous phosphoric acid, it is decomposed, and yields a mixture of three different hydrocarbons, to which the author gives the names of Cajputene, Isocajputene, and Metacajputene. The two former, though differing in properties, have both the formula C20 H16. The last, which is a very heavy oil, with a lemon yellow colour and brilliant fluorescence, is C40 H32.

scholarly journals Section XVI.—The Determination of the Specific Gravity of the Crystals of a Soluble Salt by Displacement in its own Mother-Liquor, and the Volumetric Relations between the Crystals and the Mother-Liquor which are Established by the Experiment.

1912 ◽  
Vol 49 (1) ◽  
pp. 202-225
Author(s):  
J. Y. Buchanan
Keyword(s):  
High Temperature ◽  
Specific Gravity ◽  
Diurnal Variation ◽  
Mother Liquor ◽  
Soluble Salt ◽  
Northern Europe ◽  
Dilute Solutions ◽  
Tropical Conditions

The work on the specific gravity of dilute solutions at 19·5° C. reported in the early part of this memoir was interrupted by the arrival of the great anticyclone or heatwave of the summer of 1904, during which observations at a temperature of 19·5° were quite impossible. Indeed, the temperature of the laboratory, whether by night or day, hardly ever fell below 23° C. or rose above 25° C. It persisted over Northern Europe for nearly six weeks, and produced tropical conditions, which were evidenced alike by the high temperature of the air and by its insignificant diurnal variation.

scholarly journals IV. Physico-chemical determinations at high pressures by optical methods

1913 ◽  
Vol 212 (484-496) ◽  
pp. 117-148 ◽  
Keyword(s):  
High Pressures ◽  
Optical Observations ◽  
Optical Methods ◽  
Small Glass ◽  
Physico Chemical ◽  
Glass Tubes ◽  
Pressure Bomb ◽  
The Subject ◽  
Transition Points

In the course of his well-known investigations concerning the compressibility of gases and liquids, Amagat made some series of measurements taking observations through two small glass windows fitted to his high-pressure bomb (“méthode des regards”),* and he also twice made an attempt to use a similar arrangement for the determination of melting and crystallization at high pressures. His first paper on these subjects deals with the melting and with the formation of two different kinds of crystals of carbon tetrachloride. The highest pressure employed was 1,160 atmospheres. The second paper, in which a somewhat different arrangement of the glass windows was used, deals with the crystallization of ice at temperatures below zero under the influence of high pressures.^ In a summarizing paper Amagat§states that he occasionally was able to reach pressures of about 1,600 atmospheres before the glass windows were broken, but observations were not actually made at higher pressures than 1,000 atmospheres. In this paper a sketch of the apparatus is also given. Amagat states that he met with severe difficulties during these investigations, and he has not pursued the subject further. Later melting-points and transition-points of some “liquo-crystalline” substances have been measured in Jena glass tubes up to 300 atmospheres by Hullett, and other optical observations at pressures above that of the atmosphere have been made by Rothmund (maximum 500 atmospheres), Röntgen and Zehnder, Sierstema, Liveing and Dewar, Hutton and Petavel,§§ and Duffield, but in these investigations the pressures have, as a rule, not exceeded 100 atmospheres.

Some physical properties of nickel carbonyl

1903 ◽  
Vol 71 (467-476) ◽  
pp. 427-439 ◽  
Keyword(s):  
Thermal Expansion ◽  
Specific Gravity ◽  
Physical Properties ◽  
Boiling Point ◽  
Nickel Carbonyl ◽  
Molecular Refraction ◽  
Vapour Density ◽  
The Subject

The properties of nickel carbonyl have until recently been the subject of but few investigations. Dr. Mond and his collaborators in the discovery of this remarkable substance determined some of its physical properties, including its boiling point, specific gravity, and vapour density. Subsequently Dr. Mond, in association with Professor Nasini, made observations on its molecular refraction and thermal expansion.

Gender determination of caucasoid hair using image analysis

1993 ◽  
Vol 51 ◽  
pp. 216-217
Author(s):  
T.B. Ball ◽  
W.M. Hess
Keyword(s):  
Image Analysis ◽  
Cross Sections ◽  
Scalp Hair ◽  
The Body ◽  
Equivalent Diameter ◽  
Cross Sectional ◽  
Hair Samples ◽  
Length Width ◽  
Morphological Differences

It has been demonstrated that cross sections of bundles of hair can be effectively studied using image analysis. These studies can help to elucidate morphological differences of hair from one region of the body to another. The purpose of the present investigation was to use image analysis to determine whether morphological differences could be demonstrated between male and female human Caucasian terminal scalp hair.Hair samples were taken from the back of the head from 18 caucasoid males and 13 caucasoid females (Figs. 1-2). Bundles of 50 hairs were processed for cross-sectional examination and then analyzed using Prism Image Analysis software on a Macintosh llci computer. Twenty morphological parameters of size and shape were evaluated for each hair cross-section. The size parameters evaluated were area, convex area, perimeter, convex perimeter, length, breadth, fiber length, width, equivalent diameter, and inscribed radius. The shape parameters considered were formfactor, roundness, convexity, solidity, compactness, aspect ratio, elongation, curl, and fractal dimension.

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