Heat of the liquid; height of capillary ascent.
Capillary bleeding is a general oozing from a raw surface.
The vessel is completely filled with mercury, the capillary sealed, and the vessel weighed.
in dry weather, since it promotes capillary action by reducing the soil spaces.
wide, the water from the pathways is soaked up on each side by capillary attraction, and in this way the roots secure a sufficient supply.
The vessel is filled by placing the capillary in a vessel containing the liquid and 6 gently aspirating.
He published many physical memoirs on electricity, the dilatation of liquids by heat, specific heats, capillary attraction, atomic volumes &c. as well as a treatise in 4 volumes on Fisica di corpi ponderabili (1837-1841).
The larger trunks open into each other either directly by cross branches, or a capillary system is formed.
Mile of Warsaw in 1828, who termed it a "hydrostatic air-pump without cylinders, taps, lids or stoppers," this is attained by using, both for the inlet and the outlet, vertical capillary glass tubes, soldered, the former to somewhere near the bottom, the latter to the top of the vessel.
From the bottom there leads P another fine tube, bent upwards, and then at right angles so as to be at the same level as the capillary branch.
In the breeding season the male deposits drops of sperm on a sheet of webbing, picks it up in these flasks by means of capillary attraction and carries it about until he falls in with a female.
It consists of a cylindrical tube of a capacity ranging from 10 to 50 cc., provided at the upper end with a thick-walled capillary bent as shown on the left of the figure.
Laplace was, moreover, the first to offer a complete analysis of capillary action based upon a definite hypothesis - that of forces "sensible only at insensible distances"; and he made strenuous but unsuccessful efforts to explain the phenomena of light on an identical principle.
Experiments by the capillary tube method have shown that the viscosity varies more nearly as 0 1, but indicate that the rate of increase diminishes at high temperatures.
The liquid is adjusted to the mark by withdrawing any excess from the capillary end by a strip of bibulous paper or by a capillary tube.
The space between the parts of such substances is too large to admit of capillary action; hence the water conveyed to the surface of the soil is prevented from passing upwards any further except by slow evaporation through the mulching layer.
The point of the rostrum is pressed against the surface to be pierced; then the stylets come into play and the fluid food is believed to pass into the mouth by capillary attraction.
Sammetblende or przibramite is a variety, from Przibram in Bohemia, consisting of delicate acicular or capillary crystals arranged in radiating groups with a velvety surface and yellow colour.
The apparatus devised by Ramsay and Shields consisted of a capillary tube, on one end of which was blown a bulb provided with a minute hole.
According to Rogowicz and Heidenhain, certain substances increase the quantity of lymph given off from a part by acting upon the cells of the capillary wall; they hold, in fact, that these substances are true lymphagogues.
The relation between hydrostatic pressure and the vapour pressure of a pure liquid may be obtained at once by considering the rise of liquid in a capillary tube.
Capillarity and Surface Tension.-Reference should be made to the article Capillary Action for the general discussion of this phenomenon of liquids.
It is necessary to determine the pressure exerted on the vapour by the mercury in the narrow limb; this is effected by opening the capillary and inclining the tube until the mercury just reaches the top of the narrow tube; the difference between FIG.
This reflection is suggested by the following articles: Aether; Molecule; Capillary Action; Diffusion; Radiation, Theory Of; and others.
The secreting cells never show this change, although they may become atrophied or destroyed by the pressure and the disturbance of nutrition brought about by the swollen condition of the capillary walls.
P, Osmotic or capillary pressure.
On the other hand, it is commonly thought that the single potentialdifferences at the surface of metals and electrolytes have been determined by methods based on the use of the capillary electrometer and on others depending on what is called a dropping electrode, that is, mercury dropping rapidly into an electrolyte and forming a cell with the mercury at rest in the bottom of the vessel.
p. 211, Paris, 1869) proposed an equation of the form (p+po)(v - b) =RO, in which the effect of the size of the molecules is represented by subtracting a quantity b, the " covolume," from the volume occupied by the gas, and the effect of the mutual attractions of the molecules is represented by adding a quantity po, the internal pressure, to the external pressure, p. This type of equation, was more fully worked out by van der Waals, who identified the internal pressure, po, with the capillary pressure of Laplace, and assumed that it varied directly as the square of the density, and could be written a/v 2 .
The setae are either entirely capillary or there are in addition some sigmoid setae even with bifid free extremities.
de Phys., Paris, 1900, p. 561) that the true effect of magnetization is liable to be disguised by secondary or parasitic phenomena, arising chiefly from polarization of the electrodes and from local variations in the concentration and magnetic condition of the electrolyte; these may be avoided by working with weak solutions, exposing only a small surface in a non-polar region of the metal, and substituting a capillary electrometer for the galvanometer generally used.
The simplest assumption which suffices to express the small deviations of gases and vapours from the ideal state at moderate pressures is that the coefficient a in the expression for the capillary pressure varies inversely as some power of the absolute temperature.
Acting on a principle quite different from any previously discussed is the capillary hydrometer or staktometer of Brewster, which is based upon the difference in the surface tension and density of pure water, and of mixtures of alcohol and water in varying proportions.
The products obtained by the distillation of petroleum are not in a marketable condition, but require chemical treatment to remove acid and other bodies which impart a dark colour as well as an unpleasant odour to the liquid, and in the case of lamp-oils, reduce the power of rising in the wick by capillary attraction.
The capillary tube can be raised or lowered at will by running a magnet outside the tube, and the heights of the columns are measured by a cathetometer or micrometer microscope.
Heidenhain, on the other hand, rejected entirely the filtration view of lymph-formation, believing that the passage of lymph across the capillary wall is a true secretion brought about by the secretory function of the endothelial plates.
Solids may be directly admitted to the tube from a weighing bottle, while liquids are conveniently introduced by means of small stoppered bottles, or, in the case of exceptionally volatile liquids, by means of a bulb blown on a piece of thin capillary tube, the tube being sealed during the weighing operation, and the capillary broken just before transference to the apparatus.
In some species (Spengelidae) there is a long capillary vermiform extension of the stomochord in front.
In the smaller and simpler forms the capillary networks are much reduced, but the dorsal and ventral vessels are usually present.
The capillary hydrometer consists simply of a small pipette with a bulb in the middle of the stem, the pipette terminating in a very fine capillary point.
4), consists of a vertical capillary Pump. glass tube a of about 1 mm.
4, which has a capacity of about 35 cc., provided with a capillary tube at the top, and a bent tube about 6 mm.
Thus, while increased pressure in the blood or lymph vessels may be one factor, and increased permeability of the capillary endothelium another, increased osmotic pressure in the tissues and lymph is probably the most important in the production of dropsy.
To prevent this various implements, such as disk harrows and specially constructed rollers, may be used to consolidate the upper stirred portion of the soil and place it in close capillary relationship with the lower unmoved layer.
Algae of more delicate texture than either Fucaceae or Laminariaceae also occur in the region exposed by the ebb of the tide, but these secure their exemption from desiccation either by retaining water in their meshes by capillary attraction, as in the case of Pilayella, or by growing among the tangles of the larger Fucaceae, as in the case of Polysiphonia fastigiate, or by growing in dense masses on rocks, as in the case of Laurencia pinnatifida.
Ulrich Kreusler generates the carbon dioxide in a separate apparatus, and in this case the tube is drawn out to a capillary at the end (a).
It was a favourite idea of his that chemical affinity and capillary attraction would eventually be included under the same law, and it was perhaps because of its recalcitrance to this cherished generalization that the undulatory theory of light was distasteful to him.
While this capillary movement of water is of great importance in supplying the needs of plants it has its disadvantages, since water may be transferred to the surface of the soil, where it evapo rates into the air and is lost to the land or the crop growing upon it..
Above the level of the ground-water the soil is kept moist by capillary attraction and by evaporation of the water below, by rainfall, and by movements of the ground-water; on the other hand, the upper layers are constantly losing moisture by evaporation from the surface and through vegetation.
If a thickwalled capillary tube is passed over the platinum tube and its length so adjusted that the liquid rises in it by capillary action just above the level of the tube, the spectrum may be examined directly, and the loss of light due to the passage through the partially wetted surface of the walls of the tube is avoided.
If material systems are constituted of discrete atoms, separated from each other by many times the diameter of any of them, this simple plan of exhibiting their interactions in terms of direct forces between them would indeed be exact enough to apply to a wide range of questions, provided we could be certain that the laws of the forces depended only on the positions and not also on the motions of the atoms. The most important example of its successful application has been the theory of capillary action elaborated by P. S.
Dittmar showed that this may be avoided by leading a fine, steady stream of dry gas - air, carbon dioxide, hydrogen, &c., according to the substance operated upon - through the liquid by means of a fine capillary tube, the lower end of which reaches to nearly the bottom of the flask.
By this capillary action water may be transferred to the upper layers of the soil from a depth of several feet below the surface.
The amount of moisture retained depends mainly upon the absorbability of the soil, and as it depends largely on capillary action it varies with the coarseness or fineness of the pores of the soil, being greater for soils which consist of fine particles.
The honeycomb of rock, and capillary action, retard the lighter fresh-water from sinking to the sea; the soakage from rain has therefore to move horizontally, over the strata about sea-level, seeking outlets.
These are hollow glass beads of variable density; they may be prepared by melting off pieces of very thin capillary tubing, and determining the density in each case by the method just previously described.
From this consideration we may derive Laplace's expression, as has been done by Dupre (Theorie mecanique de la chaleur, Paris, 1869), and Kelvin (" Capillary Attraction," Proc. Roy.
The surface-tension diminishes as the temperature rises, and when the temperature reaches that of the critical point at which the distinction between the liquid and its vapour ceases, it has been observed by Andrews that the capillary action also vanishes.
The early writers on capillary action supposed that the diminution of capillary action was due simply to the change of density corresponding to the rise of temperature, and, therefore, assuming the surface-tension to vary as the square of the (37)?(f) =eP f (38) density, they deduced its variations from the observed dilatation of the liquid by heat.
If a drop of alcohol be made to touch one side of a drop of oil on a glass plate, the alcohol will appear to chase the oil over the plate, and if a drop of water and a drop of bisulphide of carbon be placed in contact in a horizontal capillary tube, the bisulphide of carbon will chase the water along the tube.
" The reason why the capillary force should disappear when the transition between two liquids is sufficiently gradual will now be evident.
At each step the difference of capillary pressure is only one-quarter of that due to the sudden transition from o to a-, and thus altogether half the effect is lost by the interposition of the layer.
When the number of steps is infinite, the capillary pressure disappears altogether."
Resolving vertically we find that the weight of the liquid raised above the level must be equal to T(sin 0 2 - sin 01), and this is therefore equal to the area P 1 P 2 A 2 A 1 multiplied by gp. The form of the capillary surface is identical with that of the " elastic curve," or the curve formed by a uniform spring originally straight, when its ends are acted on by equal and T 2 opposite forces applied either to the ends themselves or to solid pieces attached to them.
The Weight Is Sometimes Equated To The Product Of The Capillary Tension (T) And The Circumference Of The Tube (27Ra), But With Little Justification.
We Will Assume That When, As In Most Cases, Viscosity Maybe Neglected, The Mass (M) Of A Drop Depends Only Upon The Density (V), The Capillary Tension (T), The Acceleration Of Gravity (G), And The Linear Dimension Of The Tube (A).
He has constructed a capillary electrometer by which differences of electric potential less than o oi of that of a Daniell's cell can be detected by the difference of the pressure required to force the mercury to a given point of a fine capillary tube.
The capillary tension endeavours to contract the surface of the fluid; so that the stability, or instability, of the cylindrical form of equilibrium depends upon whether the surface (enclosing a given volume) be greater or less respectively after the displacement than before.
On this point Plateau's explanations are not very clear, and he sometimes expresses himself as if the time of disintegration depended only upon the capillary tension, without reference to initial disturbances at all.
Such collisions are inevitable in consequence of the different velocities acquired by the drops under the action of the capillary force, as they break away irregularly from the continuous portion of the jet.
No change in the capillary conditions can arise until the interval is reduced to a small fraction of a wave-length of light; but such a reduction, unless extremely local, is strongly opposed by the remaining air.
Extremely local contacts of the liquids, while opposed by capillary tension which tends to keep the surfaces flat, are thus favoured by the electrical forces, which moreover at the small distances in question act with exaggerated power.
If h is the height to which the liquid will rise in a capillary tube of unit radius, then the diameter of the largest orifice is 2a =3.8317 A / (2h) = 5.4188-J (h).
A calculation analogous to that of Lord Kelvin may be applied to find the frequency of small transverse vibrations of a cylinder of liquid under the action of the capillary force.
A formula, similar to (5), may be given for the frequencies of vibration of a spherical mass of liquid under capillary force.
A widespread toxic action is indicated by the lesions found - cloudy swelling, which may be followed by fatty degeneration, in internal organs, capillary haemorrhages, &c. In septicaemia.
The mixture is placed in a thin capillary tube and incubated at 37° C. for half an hour; a film preparation is then made from it on a glass slide, stained by a suitable method and then examined microscopically.
An early observation of the diffusion of gases was recorded by him in 1823 when he noticed the escape of hydrogen from a cracked jar, attributing it to the capillary action of fissures.
He was the first to use the vacuum tube with the capillary part now called a Geissler's tube, by means of which the luminous intensity of feeble electric discharges was raised sufficiently to allow of spectroscopic investigation.
Such a saltwater saucer of fresh water is maintained full to overflowing by the rainfall, and owing to the frictional resistance of the sand and to capillary action and the fact that a given column of fresh water is balanced by a shorter column of sea water, the fresh water never sinks to the mean sea-level unless artificially abstracted.
The water, contained in the interstices of the sand above the mean sea-level, would (except in so far as a film, coating the sand particles, is held up by capillary attraction) gradually sink to the sea-level if there were no rainfall.
Small, however, as the micro-organisms are, they are larger than the capillary passages in some materials through which water under pressure may be caused to percolate.
Drains ordinarily remove only excess of capillary water, an excess of percolating water in wet weather.
One tube, called the "measuring tube," is provided with a capillary stopcock at the top and graduated downwards; the other tube, called the "level tube," is plain and open.
The lower bulb is provided with a smaller bulb bearing a capillary through which the gas is led to the apparatus, the higher bulb has a wider outlet tube.
To use a pipette, the absorbing liquid is brought to the outlet of the capillary by tilting or by squeezing a rubber ball fixed to the wide end, and the liquid is maintained there by closing with a clip. The capillary is connected with the measuring tube by a fine tube previously filled with water.
Hydrogen may be estimated by absorption by heated palladium contained in a capillary through which the gas is passed, or by exploding (under reduced pressure) with an excess of oxygen, and measuring the diminution in volume, two-thirds of which is the volume of hydrogen.
At the top it is connected by a capillary tube bent at right angles to a series of absorbing vessels, the connexion being effected by stopcocks.
The cylinder in direct communication with the capillary is filled with glass tubes so as to expose a larger surface of the absorbing solution to the gas.
Any number of bulbs can be attached to the horizontal capillary; in the form illustrated there are four, the last being a hydrogen pipette in which the palladium is heated in a horizontal tube by a spirit lamp. At the end of the horizontal tube there is a three way cock connecting with the air or an aspirator.
completely to fill the bulbs nearer the capillary.
He also wrote essays and short stories, and an English version of Tolstoi's Sebastopol (1887); and among his publications are The Danube (1891), Capillary Crime and other Stories (1892), and Expedition to the Philippines (1899).
arteriovenous shunts without any intervening capillary network.
This process is normally complete by the time the blood has passed about one third of the way along the pulmonary capillary.
capillary matting is then cut to fit the lid.
capillary electrophoresis with 16 capillaries operating in parallel.
capillary rheometers are highly valuable for simulating high shear rate conditions.
capillary extrusion rheometry.
In normal circumstances, fluid moves through the blood capillary wall into the interstitial tissues (Stanton, 2000 ).
Mercury thermometer A glass bulb filled with mercury is connected to a narrow evacuated glass capillary tube.
capillary that the blood vessel leaving a glomerulus is narrower than the one entering it and so pressure in the glomerular capillaries is high.
capillary, the view of the choroidal vessels and retinal capillaries is soon obscured by the rapid leakage of fluorescein from the choroidal vasculature.
Wax content - determined by capillary column gas-liquid chromatography (GLC) for detecting the addition of solvent extracted olive pomace oil.
capillary condensation is a further action effective in the boundary pores on the strength of monomolecular deposition.
To cool the sample, liquid cryogen is drawn from the helium reservoir, through a capillary tube and into a heat exchanger.
damp proofing: In the 18th century it was discovered that an applied voltage affected capillary action.
The range of techniques in which the unit is particularly experienced includes capillary electrophoresis, electrochromatography and HPLC.
The new service which uses the ABI PRISM 3100, a fluorescence-based DNA analysis system incorporating capillary electrophoresis with 16 capillaries operating in parallel.
endotheliumion of the aquaporin CHIP in secretory and resorptive epithelia and capillary endothelia.
The proportion of bound and free labeled peptides was determined using free-zone capillary electrophoresis and laser-induced fluorescence.
A piece of capillary matting is then cut to fit the lid.
Exudate - the fluid plasma which leaks out of blood vessels due to an increase in capillary permeability.
propagation of intense laser pulses through capillary tubes was undertaken.
In addition, the propagation of intense laser pulses through capillary tubes was undertaken.
There is an associated increase in capillary fragility which presumably can account for the occasional cases of non- thrombocytopenic purpura.
Observe the effect on CVP, blood pressure, pulse, urine output and capillary refill.
The measurement of extrudate swell of polymer melts using capillary extrusion rheometers is specified by the standard ISO 11443  .
ISO 11443: Plastics - Determination of the fluidity of plastics using capillary and slit die rheometers.
These small molecules pass through the renal tube (coiled tubule) which is surrounded by a capillary network.
With these goals in mind, we have designed a new type of capillary discharge waveguide with a square cross-section.
It is there shown that the surface tension of a liquid may be calculated from its rise in a capillary tube by the formula y = rhs, where y is the surface tension per square centimetre, r the radius of the tube, h the height of the liquid column, and s the difference between the densities of the liquid and its vapour.
The members of the first class influence the endothelial plates of the capillaries injuriously, inducing thereby increased permeability; those of the second class (sugar, &c.), on injection into the blood, attract water from the tissues and cause a condition of hydraemic plethora with increased capillary pressure.
to xxxii., including accounts of some interesting experiments in magnetism and capillary attraction.
According to Maxwell, priority in showing the necessity for slipping over the boundary rests with Reynolds, who also discovered the cognate fact of thermal transpiration, meaning thereby that gas travels up the gradient of temperature in a capillary tube, owing to surface-actions, until it establishes such a gradient of pressure (extremely minute) as will prevent further flow.
Soc., 1890, 47, p. 364), who found that a film of olive oil spread over the surface of water produced a perceptible effect on small floating pieces of camphor, at places at which the thickness of the film was io 6 X10 -8 cms., but produced no perceptible effect at all at places where the thickness of the film was 8.1 X10 -8 cms. Thus a certain phenomenon, of the nature of capillary action, is seen to depend for its existence on the linear dimensions of the film of oil; the physical properties of a film of thickness Io 6Xio 8 cms. are found to be in some way qualitatively different from those of a film of thickness 8.1 X io 8 cms. Here is proof that the film of oil is not a continuous homogeneous structure, and we are led to suspect that the scale on which the structure is formed has a unit of length comparable with 8 X10 -8 cms. The probability of this conjecture is strengthened when it is discovered that in all phenomena of this type the critical length connected with the stage at which the phenomenon changes its nature is of the order of magnitude of 10 -8 cms.
Discussing the theory of capillary attractions, Young' found that at a rough estimate " the extent of the cohesive force must be limited to about the 250-millionth of an inch " (=10 8 cms.), and then argues that " within similar limits of uncertainty we may obtain something like a conjectural estimate of the mutual distance of the particles of vapours, and even of the actual magnitude of the elementary atoms of liquids..
Morthoe, Luton Hoo, the Hoe at Plymouth, &c.; this is the same as Northern English "heugh" and is connected with "hang"), an agricultural and gardening implement used for extirpating weeds, for stirring the surface-soil in order to break the capillary channels and so prevent the evaporation of moisture, for singling out turnips and other root-crops and similar purposes.
At he same time he brought forward another determination bas Ã‚° d on the heating effects observable when water is forced through capillary tubes; the number obtained in this way was 77 o A third method, depending on the observation of the heat evo ved by the mechanical compression of air, was employed a yea or two later, and yielded the number 798; and a fourth - the wel -known frictional one of stirring water with a sort of paddlewh:el - yielded the result 890 (see Brit.
& is immersed, there is a liability to error in consequence of the surface tension, or capillary action, as it is frequently called, along the line of contact of the instrument and the surface of the liquid (see Capillary Action).
We have given several examples in which the density is assumed to be uniform, because Poisson has asserted that capillary B (25) e = c p (X' - 4 7rpe (0) ) -I-474Ã‚°o(z)dz.
The changes produced at a distance by distribution of toxins may be very manifold - cloudy swelling and fatty degeneration, serous effusions, capillary haemorrhages, various degenerations of muscle, hyaline degeneration of small blood-vessels, and, in certain chronic diseases, waxy degeneration, all of which may be widespread, are examples of the effects of toxins, rapid or slow in action.
The mixture is placed in a thin capillary tube and incubated at 37Ã‚° C. for half an hour; a film preparation is then made from it on a glass slide, stained by a suitable method and then examined microscopically.
The measurement of extrudate swell of polymer melts using capillary extrusion rheometers is specified by the standard ISO 11443 [6 ].
Capillary refill time: Pressing your finger against your dog's gums will cause the blood to be pushed out of the spot you touch.
The blood sample is drawn in tiny capillary tubes, properly labeled, and taken to the laboratory for testing.
Telangiectasia-Abnormal dilation of capillary blood vessels leading to the formation of telangiectases or angiomas.
The term telangiectasia refers to a spot formed, usually on the skin, by a dilated capillary or terminal artery.
The blood sample is drawn into tiny capillary tubes, properly labeled, and taken to the laboratory for testing.
When this occurs, they precipitate out and become lodged in the capillaries, which can cause the capillary to burst, resulting in a local hemorrhage.
Lam, Samuel, et al. "Practical Considerations in the Treatment of Capillary Vascular Malformations, or Port Wine Stains."
About 65 percent are capillary hemangiomas (strawberry marks), 15 percent are cavernous (deep) hemangiomas, and the rest are mixtures.
Capillary hemangiomas: Fewer than 10 percent need treatment.
Vitamin E may help prevent hair loss and promote hair growth by supporting capillary growth.
The wick draws the flammable liquid up from the holding tank through a process known as capillary action.
The wick absorbs the melted wax and through capillary action draws the melted wax up the wick toward the flame.
The chief varieties of haemorrhage are arterial, venous and capillary.
The bringing of the liquid to the mark is effected by removing the excess by means of a capillary.
capilla), is called a capillary tube.
The action between the capillary tube and the water has been called capillary action, and the name has been extended to many other phenomena which have been found to depend on properties of liquids and solids similar to those which cause water to rise in capillary tubes.
p. 551), Leonardo da Vinci must be considered as the discoverer of capillary phenomena, but the first accurate observations of the capillary action of tubes and glass plates were made by Francis Hawksbee (Physico-Mechanical Experiments, London, 1709, pp. 13916 9; and Phil.
He considered the capillary phenomena to be of the same kind, but his explanation is not sufficiently explicit with respect to the nature and the limits of the action of the attractive force.
In like manner we may by experiment ascertain the general fact that the surface of a liquid is in a state of tension similar to that of a membrane stretched equally in all directions, and prove that this tension depends only on the nature and temperature of the liquid and not on its form, and from this as a secondary physical principle we may deduce all the phenomena of capillary action.
des Sciences, 1787, p. 506) asserted that " by supposing the adherence of the particles of a fluid to have a sensible effect only at the surface itself and in the direction of the surface it would be easy to determine the curvature of the surfaces of fluids in the neighbourhood of the solid boundaries which contain them; that these surfaces would be linteariae of which the tension, constant in all directions, would be everywhere equal to the adherence of two particles, and the phenomena of capillary tubes would then present nothing which could not be determined by analysis."
Leslie's theory was afterwards treated according to Laplace's mathematical methods by James Ivory in the article on capillary action, under "Fluids, Elevation of," in the supplement to the fourth edition of the Encyclopaedia Britannica, published in 1819.
Trans., 1805, p. 65) founded the theory of capillary phenomena on the principle of surface-tension.
He also observed the constancy of the angle of contact of a liquid surface with a solid, and showed how from these two principles to deduce the phenomena of capillary action.
Having applied the secondary principle of surface-tension to the various particular cases of capillary action, Young proceeded to deduce this surface-tension from ulterior principles.
The form into which he threw his investigation seems to have deterred many able physicists from the inquiry into the ulterior cause of capillary phenomena, and induced them to rest content with deriving them from the fact of surface-tension.
He thus found for the pressure at a point in the interior of the fluid an expression of the form p =K+ZH(1/R+i/R'), where K is a constant pressure, probably very large, which, however, does not influence capillary phenomena, and therefore cannot be determined from observation of such phenomena; H is another constant on which all capillary phenomena depend; and R and R' are the radii of curvature of any two normal sections of the surface at right angles to each other.
In the Supplement to the Theory of Capillary Action, Laplace deduced the equation of the surface of the fluid from the condition that the resultant force on a particle at the surface must be normal to the surface.
He proceeded to an investigation of the equilibrium of a fluid on the hypothesis of uniform density, and arrived at the conclusion that on this hypothesis none of the observed capillary phenomena would take place, and that, therefore, Laplace's theory, in which the density is supposed uniform, is not only insufficient but erroneous.
We have now described the principal forms of the theory of capillary action during its earlier development.
A good account of the subject from a mathematical point of view will be found in James Challis's " Report on the Theory of Capillary Attraction," Brit.
de Chimie et de Physique, 1866-1868) applied the principles of thermodynamics to capillary phenomena, and the experiments of his son Paul were exceedingly ingenious and well devised, tracing the influence of surfacetension in a great number of very different circumstances, and deducing from independent methods the numerical value of the surface-tension.
Theory Of Capillary Action When two different fluids are placed in contact, they may either diffuse into each other or remain separate.
The experiments of Quincke and others seem to show that the extreme range of the forces which produce capillary action lies between a thousandth and a twenty-thousandth part of a millimetre.
It is easy to show that a force subject to this law would not account for capillary action.
The time of vibration is of course itself a function of the nature of the fluid and of the size of the drop. By the method of dimensions alone it may be seen that the time of infinitely small vibrations varies directly as the square root of the mass of the sphere and inversely as the square root of the capillary tension; and it may be proved that its expression is - V C?
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