scholarly journals VII. On the Influence of the Air in determining the Crystallization of Saline Solutions

1828 ◽  
Vol 11 (1) ◽  
pp. 114-118
Author(s):  
Thomas Graham
Keyword(s):  
Atmospheric Pressure ◽  
Solid Particles ◽  
Saturated Solution ◽  
Satisfactory Explanation ◽  
Adequate Explanation ◽  
Great Excess ◽  
The Subject ◽  
Saline Solutions ◽  
Crystalline Mass

The phenomenon referred to has long been known, and popularly exhibited in the case of Glauber's salt, without any adequate explanation. A phial or flask is filled with a boiling saturated solution of sulphate of soda or Glauber's salt, and its mouth immediately stopped by a cork, or a piece of bladder is tied tightly over it, while still hot. The solution, thus protected from the atmosphere, generally cools without crystallizing, although it contains a great excess of salt, and continues entirely liquid for hours and even days. But upon withdrawing the stopper, or puncturing the bladder, and admitting air to the solution, it is immediately resolved into a spongy crystalline mass, with the evolution of much heat. The crystallization was attributed to the pressure of the atmosphere suddenly admitted, till it was shewn that the same phenomenon occurred, when air was admitted to a solution already subject to the atmospheric pressure. Recourse was likewise had to the supposed agency of solid particles floating in the air, and brought by means of it into contact with the solution; or it was supposed that the contact of gaseous molecules themselves might determine crystallization, as well as solid particles. But although the phenomenon has been the subject of much speculation among chemists, it is generally allowed that no satisfactory explanation of it has yet been proposed.

Phenomena of the capillary electroscope

1881 ◽  
Vol 32 (212-215) ◽  
pp. 85-103 ◽  
Keyword(s):  
Aqueous Solutions ◽  
Liquid Metals ◽  
Mechanical Effect ◽  
Solid Particles ◽  
Electric Currents ◽  
Capillary Action ◽  
Liquid Diffusion ◽  
Du Bois ◽  
High Tension ◽  
The Subject

In a communication “On the Capillary Electroscope” (“Proc. Roy. Soc.,” vol. 30, p. 32), I have described various details necessary to be attended to in the construction and use of a modified form of that apparatus, and I now give an account of an investigation I have made of the phenomena of the movements of the mercury in such instruments. A research I formerly made, “On the Movements of Liquid Metals and Electrolytes in the Voltaic Circuit" ("Proc. Roy. Soc.,” vol. 10, p. 235), throws additional light upon the subject. Some of the phenomena arising out of this research have, for the sake of convenience, been made the subjects of separate communications. (See “Effects of Electric Currents on the Surface of Mutual Contact of Aqueous Solutions," "Proc. Roy. Soc.,” vol. 30, p. 322, ibid ., vol. 31, p. 250; "Influence of Electric Currents on Diffusion of Liquids;" "Experiments on Electric Osmose;” "Electric Currents caused by Liquid Diffusion and Osmose,” ibid ., vol. 31, p. 253, ibid., vol. 31, p. 296.) Erman, in the year 1809, appears to have been the first to observe the movements of mercury in a conducting solution while under the influence of an electric current. Since that time a large number of investigators have examined the phenomenon and the allied ones of electric osmose, electro-capillary action, electric currents produced by capillarity, the mechanical effect of electric currents upon liquids and upon solid particles suspended in them, &c. Among these are Armstrong, E. Becquerel, Buff, H. Davy, Draper, Du Bois Reymond, Faraday, Heidenhain, Hellwig, Herschel, Hittorf, Jürgensen, Kühne, Lippmann, Logeman, Matteucci, Paalzow, Pfaff, Poggendorff, Porrett, Quincke, Reichert, Reuss, Runge, Sabine, Serullas, Varley, Wheatstone, Wiedemann, and Wright. It is difficult, therefore, to entirely avoid restatement of some of the results arrived at by these investigators. I have examined the movements in relation to a variety of conditions, some of which, however, are unessential and may he eliminated or diminished. The phenomena have been found to he purely physical, except in those cases where the electricity was of too high tension and produced electrolysis, and in those in which the solution acted chemically upon the mercury.

Contributions to the chemistry of the urine; on the variations in the alkaline and earthy phosphates in the healthy state, and on the alkalescence of the urine from fixed alkali

1851 ◽  
Vol 5 ◽  
pp. 561-562
Keyword(s):  
Calcium Sulphate ◽  
The Other ◽  
Test Paper ◽  
Healthy State ◽  
Great Excess ◽  
Acid Reaction ◽  
The Subject ◽  
Alkaline Phosphate ◽  
The One ◽  
Amorphous Precipitate

The author, having observed that in some states of disease there occurs in the urine a great excess of the earthy phosphates, was in­ duced to investigate the subject; and as a preliminary inquiry, to ascertain the variations in the amount of these phosphates at differ­ent times in the same person in a state of health, and to trace the causes which determine an excess or a deficiency of these salts in the urine; noting, at the same time, the variations in the quantity of the alkaline phosphates contained in it, with a view of discovering whether these variations are influenced by the same, or by different causes. The principal results to which his experiments have con­ducted him are the following. The quantity of the earthy phos­phates in the urine voided soon after taking food is considerably greater than in that voided at other times ; and this happens whether the meal consists of animal food or of bread only. After long fast­ing, the proportion of earthy phosphates is considerably diminished. On the other hand, the alkaline phosphates are present in greatest quantity when the food consists of bread alone : when meat alone is taken, the deficiency in those salts is still more marked than the excess in the former case. Exercise occasions no change in the quantity of the earthy phosphates, but causes an increase of nearly one-third in the amount of alkaline phosphates ; but its influence is, on the whole, less than that of diet. The earthy phosphates are in­ creased in quantity by chloride of calcium, sulphate of magnesia, and calcined magnesia taken into the stomach. The author next examines the conditions in which the urine is alkalescent, and which he considers to be of two kinds ; the one, long known as ammoniacal , and arising from the presence of carbonate of ammonia; and the other, which has not hitherto been distinctly re­cognised, arising from fixed alkali, and appearing most frequently in urine secreted during a period of from two to four hours after breakfast, in persons suffering only from defective digestion. Under these circumstances, it may be, when voided, either turbid from amorphous sediment, or clear and alkaline when tested, or free from deposit and slightly acid. If in either of these last cases it be heated, an amorphous precipitate falls down, which is soluble in dilute hy­drochloric acid, or in a solution of biphosphate of soda. Healthy urine may at any time be made to yield a precipitate of earthy phos­phates by heat, even though it be acid, by having a portion of this acid neutralised by any alkali, or by phosphate of soda, the fluid becoming more acid when boiled. A solution of earthy phosphates in biphosphate of soda also gives a precipitate on boiling, if some of its acid reaction is removed by any alkali. The fluid when boiled becomes more acid to test-paper, indicating the formation of a more basic earthy phosphate. A result precisely similar is obtained when common phosphate of soda, phosphate of lime, and a little biphos­phate of soda exist together in solution ; and by varying the quan­tities of each of these substances, the various phenomena which the urine occasionally presents may be imitated. The time at which the alkalescence of the urine from fixed alkali generally occurs, indi­cates the existence of some alkaline phosphate, or of some carbonated alkali in the food.

scholarly journals III. On the function of the sides of the vessel in maintaining the state of supersaturation

1878 ◽  
Vol 27 (185-189) ◽  
pp. 189-195
Keyword(s):  
The State ◽  
Consistent Theory ◽  
The Subject ◽  
Saline Solutions ◽  
Experimental Researches

Before any consistent theory can be framed of all the phenomena of supersaturated saline solutions, it is necessary to determine whether the sides of the vessel bear any, and what part, in maintaining the state of supersaturation. It is remarkable that among the multitude of memoirs and papers that have been published on the subject of supersaturation generally, and of special phenomena in particular, my reading should not have made me acquainted with any special experimental researches conducted with the view of determining the point in question.

scholarly journals On the inter-crystalline fracture of metals under prolonged application of stress (Preliminary paper)

1919 ◽  
Vol 96 (674) ◽  
pp. 55-68 ◽  
Keyword(s):  
Practical Importance ◽  
Point Of View ◽  
Exact Nature ◽  
Satisfactory Explanation ◽  
Fundamental Interest ◽  
Crystalline Fracture ◽  
Satisfactory Account ◽  
The Subject ◽  
Cartridge Cases ◽  
Type Of Failure

The authors have recently made a series of observations on some cases of inter-crystalline fracture in various metals, occurring as the result of the prolonged application of stress. In explanation of these phenomena they have formulated an hypothesis which appears to afford a satisfactory account of the present observations and to correlate them with other well-known phenomena whose exact nature has, however, hitherto remained obscure. In putting their observations and hypothesis on record at the present stage, the authors are well aware that much fuller experimental investigation of the whole subject is required, and they hope to carry this forward. The evidence now available, however, appears to them to justify preliminary publication, especially in view of the fundamental interest and great practical importance of the subject. The present paper relates to a group of phenomena some of which have long been known, in the case of brass, as “season cracking.” Brass articles which have been manufactured by a process of alternate cold-working and annealing—such, for instance, as cartridge-cases and other articles made by operations of cupping and drawing—sometimes exhibit a tendency, after a period which may vary from a few hours to several years, to undergo spontaneous cracking. The occurrence of this type of failure of brass has been a serious manufacturing difficulty and much study has been given to the subject; as a result, modifications of both the annealing and the drawing processes have been made, which, to a considerable extent, eliminate the trouble. A satisfactory explanation of “season cracking” has not, however, been put forward so far as the authors are aware. From the present point of view, perhaps the most interesting fact which has been observed about "season cracking” in brass is that the fracture—in those cases where its path can be traced clearly among the micro-constituents of the metal—markedly follows the inter-crystalline boundaries. An example of such a crack is illustrated, under a magnification of 100 diameters, in fig. 1, where the inter-crystalline character of the fracture can be clearly traced (Plate 1).

Problems related to the tests of resistance and strength of military equipment in reduced atmospheric pressure conditions

2019 ◽  
Vol 124 ◽  
pp. 151-159
Author(s):  
Patryk Płochocki ◽  
Mateusz Makarewicz ◽  
Przemysław Simiński
Keyword(s):  
High Altitude ◽  
Working Conditions ◽  
Atmospheric Pressure ◽  
Ambient Pressure ◽  
Air Transport ◽  
Normative Documents ◽  
Military Equipment ◽  
The Subject

This article is about military equipment research in conditions of reduced atmospheric pressure. Reported cases of equipment damage during work at high altitude or air transport show the need to perform research on phenomena occurring during storage, transport and operation of equipment at a reduced ambient pressure. One of the fragments of the article is devoted to the records contained in normative documents regarding the subject of the study. In addition, an exemplary experiment was made, the purpose of which was to illustrate some of the effects associated with the use of the equipment in the above-mentioned working conditions.

1. Twenty-fourth Report of the Commissioners in Lunacy to the Lord Chancellor. 1870. 2. Twelfth Annual Report of the General Board of Commissioners in Lunacy for Scotland. 1870

1870 ◽  
Vol 16 (75) ◽  
pp. 426-437
Author(s):  
T. S. C.
Keyword(s):  
Death Rate ◽  
Annual Report ◽  
Vital Statistics ◽  
Satisfactory Explanation ◽  
The Third ◽  
Fourth Report ◽  
True Conclusion ◽  
The Subject ◽  
Lord Chancellor ◽  
First Time

The number of persons in Great Britain registered as insane is now 62,023. Of these 54,713 are English and 7,310 Scotch. Ten years ago the numbers were 39,647 and 6,251, or 45,898 in all. An increase of 16,125 lunatics in ten years in this country is a most noteworthy fact. It has hitherto received no thoroughly satisfactory explanation. We can conceive of no question the solution of which would be more interesting medically, socially, and economically. It is to be earnestly hoped that the Commissioners in Lunacy will soon attempt it. They alone have the materials for working it out. They have already put forward partial explanations, or rather theories, supported by a certain amount of fact. But the subject in all its bearings is still in want of a satisfactory handling. All the facts and figures that bear on (1st) the cases registered as insane for the first time each year, (2nd) the mortality among the insane, (3rd) their mode of accommodation and treatment in each district from year to year, and (4th) the cases left as insane at the end of each year, would require to be ascertained and carefully considered before a true conclusion could be arrived at. Under the first heading a comparison of the numbers of well marked cases of the different varieties of recent insanity occurring each year would require to be made. And all the truth could not be got until a similar comparison of the varieties of chronic cases for the first time registered as insane each year was made, and also an attempt to discover the original forms of their insanity, the treatment to which they had been subjected, and its influence on their malady. Under the second heading, the death rate in each variety of insanity under the different kinds of treatment and distribution, the prospects of life and “natural termination” of the chronic cases, would have to be studied and compared with the numbers of new cases registered each year, and with the death rate and rapidity of increase of the population at large. The third point referred to would enable corrections to be made for certain counties in which changes in the accommodation for the insane had been made, and then all the preceding vital statistics applied to the figures under the fourth heading would bring out the whole truth in regard to the subject. In the Scotch report there is a new and able effort to take the question of age into account in dealing with the vital statistics of the insane; but unfortunately the chief value of the facts are not brought out, by not comparing them with the returns of the Registrar-General in regard to the numbers of the general population of different ages.

Rubber Heat Engines, Analyses and Theory

1979 ◽  
Vol 52 (1) ◽  
pp. 159-172 ◽  
Author(s):  
R. J. Farris
Keyword(s):  
Heat Source ◽  
Atmospheric Pressure ◽  
Heat Engine ◽  
Working Fluid ◽  
Thermodynamic Behavior ◽  
The Past ◽  
Heat Engines ◽  
Pressure Steam ◽  
The Subject ◽  
Power Densities

Abstract It has long been known that elastomeric solids could be used as the working “fluid” in engines designed to convert heat into mechanical work. In the past rubber heat engine cycles were not given serious consideration since energy alternatives were not in demand and the majority of the scientific community is unaware of their gas-like thermodynamic behavior. Consequently, past work has dealt with the subject primarily as a novelty or as a demonstrative proof of thermodynamic behavior. This paper provides an idealized mechanical and thermodynamic analysis of the rubber cycle and compares it to an equivalent cycle wherein a gas is the working fluid. Experimental data on a small rubber fiber engine are included which confirms the high power potential of these engines when they are designed using modern elastomeric fibers. These materials have remarkable properties and can respond rapidly to cyclic thermal disturbances. Power densities of roughly one watt/g of rubber have been attained using only a 30°C difference between the heat source and heat sink. Engine speeds well over 1000 rpm have also been attained when atmospheric pressure steam was used as the heat source. The analyses demonstrate that elastomers are ideally suited for energy conversion when only small temperature differences are available.

I. Preliminary notice of experiments concerning the chemical constitution of saline solutions

1874 ◽  
Vol 22 (148-155) ◽  
pp. 241-243
Keyword(s):  
Absorption Spectra ◽  
Saturated Solution ◽  
Chemical Action ◽  
Chemical Constitution ◽  
Copper Chromium ◽  
Saline Solutions ◽  
Cobalt Copper

The author has been engaged in investigating the above subject during the last eighteen months, and his experiments being still in progress, he thinks it desirable to place the following observations on record. In the examination of the absorption-spectra, as seen in wedge-shaped cells, of the principal salts of cerium, cobalt, copper, chromium, didymium, nickel, palladium, and uranium, to the number of nearly sixty different solutions, it was noticed that the properties of the substances in regard to changes of colour could be ascertained by noticing the absorption-curves and bands, so that, provided water be without chemical action, it could be foreseen what change would occur on dilution of a saturated solution.

scholarly journals Diffusion of CCTs from Latin America to Asia: the Philippine 4Ps case

2018 ◽  
Vol 52 (2) ◽  
pp. 264-284 ◽  
Author(s):  
Michael Howlett ◽  
M Ramesh ◽  
Kidjie Saguin
Keyword(s):  
Policy Instruments ◽  
Conditional Cash Transfer ◽  
The Philippines ◽  
Policy Transfer ◽  
Cash Transfer ◽  
Adequate Explanation ◽  
The Past ◽  
The Subject

Abstract The purpose of this study is to understand the role of international and domestic actors, ideas and processes in the diffusion of public policies. It argues that existing studies on the subject do not provide an adequate explanation of the mechanisms through which diffusion takes place, nor do they sufficiently address the roles of actors affecting the policy transfer process. We address these shortcomings by studying the diffusion of conditional cash transfer (CCT) programs from Brazil and Mexico to the Philippines over the past decade. We use the concept of an ‘instrument constituency’ to delineate and trace the various actors and channels involved in the diffusion of CCTs. The case study shows that these groups of actors dedicated to the articulation, adoption and expansion of particular policy instruments are central players in transnational diffusion of policies and offer a robust explanation of the phenomenon.

Barometrical observations, showing the effect of the direction of the wind on the difference between distant barometers

1843 ◽  
Vol 4 ◽  
pp. 386-387
Keyword(s):  
Atmospheric Pressure ◽  
The North ◽  
Heating And Cooling ◽  
Westerly Winds ◽  
Different Seasons ◽  
The Subject ◽  
The Difference ◽  
The Times ◽  
The One

The author institutes a comparison between the barometric heights as observed at the Apartments of the Royal Society, and at his house in Herefordshire, in the neighbourhood of Ross, with a view to ascertain the influence of prevailing winds on the atmospheric pressure. The barometers thus compared together were of the same construction, and by the same maker; and the times of observation, namely nine o’clock a. m. and three o’clock p. m., were the same at both places, the distance between which is 110 miles in longitude, and about 20 in latitude. The degree of accordance in the march of the two barometers is exhibited by that of curves traced on three sheets accompanying the paper. The results are given in eight tables. The author agrees with Schubler in ascribing the currents prevailing in the atmosphere to the variable relations of heating and cooling which obtains between the Atlantic Ocean and the continent of Europe at different seasons; the facts ascertained by the series of observations here presented being in accordance with that hypothesis. If the northerly and westerly winds in England be partly the effect of the expansion of the air on the continent, then the barometer which is nearest to the continent, or in this instance that at London, ought to be relatively more depressed than the one more distant; or if the southerly and easterly winds be regarded as proceeding to the ocean, then, for a similar reason, the barometer nearest to the ocean ought to be relatively depressed; and that both these effects are produced, is shown by the tables. This view of the subject also, the author remarks, is corroborated by Raymond’s observations, detailed in his memoir on the determination of the height of Clermont Ferrand, from which it appears that with the north winds, the southern barometer was most depressed; while the reverse occurred with the southerly winds.

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