Colloid Chemistry: An Introduction, with Some Practical Applications |
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action adsorbed adsorption adsorption compound albumen alkali beam blood blue casein cent CHARGE AND MIGRATION Chem chemical clay coagulation COLLOID CHEMISTRY colloidal dispersion colloidal gold colloidal gold solution colloidal particles colloidal protection Colloidal silver colloidal solutions color constituent cow's milk crystalloid crystalloid solutions dextrin dialyzer diameter differential diffusion dilute dispersed phase dissolved dition dyestuffs effect electrolytes emulsion enzyme fact ferric fiber filter filtration fluid formed gelatin gold particles gum arabic hydrated hydrosol ice cream individual particles ions irreversible jellies light cone Liquid loidal loids matter metals microscope molecule negatively charged oxid particles of colloidal peptization potash precipitate produced properties of colloids protective colloids Purple of Cassius quantities reversible colloids salts selective adsorption septum silicic acid smaller sodium chlorid Solid soluble stannic acid starch surface suspension swelling Table tannin tion tissues transparent soap true crystals ultra ultramicrons ultramicroscope visible whereas Zsigmondy μμ
Popular passages
Page 6 - It is difficult to avoid associating the inertness of colloids with their high equivalents, particularly where the high number appears to be attained by the repetition of a smaller number. The inquiry suggests itself whether the colloid molecule may not be constituted by the grouping together of a number of smaller crystalloid molecules, and whether the basis of colloidality may not really be this composite character of the molecule.
Page 3 - As gelatine appears to be its type, it is proposed to designate substances of the class as colloids, and to speak of their peculiar form of aggregation as the colloidal condition of matter.
Page 2 - fixed" class, as regards diffusion, is represented by a different order of chemical substances, marked out by the absence of the power to crystallize, which are slow in the extreme. Among the latter are hydrated silicic acid, hydrated alumina, and other metallic peroxides of the aluminous class, when they exist in the soluble form ; together with starch, dextrin, and the gums, caramel, tannin, albumen, gelatin, vegetable, and animal extractive matters.
Page 4 - Although chemically inert in the ordinary sense, colloids possess a compensating activity of their own, arising out of their physical properties. While the rigidity of the crystalline structure shuts out external impressions, the softness of the gelatinous colloid partakes of fluidity, and enables the colloid to become a medium for liquid diffusion, like water itself.
Page 2 - Low diffusibility is not the only property which the bodies last enumerated possess in common. They are distinguished by the gelatinous character of their hydrates. Although often largely soluble in water, they are held in solution by a most feeble...
Page 34 - Gelatinous stannic acid also is easily liquefied by a small proportion of alkali, even at the ordinary temperature. The alkali, too, after liquefying the gelatinous colloid, may be separated again from it by diffusion into water upon a dialyzer.
Page 8 - News," Vol. 65, p. 90 [1892], stated as follows: " I am disposed to conclude that solution is nothing but subdivision and admixture, owing to attractions between solvent and dissolved substance accompanied by pedetic motion; that the true osmotic pressure has, probably, never been measured; and that a continuous passage can be traced between visible particles in suspension, and matter in solution; that, in the words of the old adage, Natura nihilfit per saltum.
Page 5 - The solution of hydrated silicic acid, for instance, is easily obtained in a state of purity, but it cannot be preserved. It may remain fluid for days or weeks in a sealed tube, but is sure to gelatinize and become insoluble at last. Nor does the change of this colloid appear to stop at that point; for the mineral forms of silicic acid, deposited from water, such as flint, are often found to have passed, during the geological ages of their existence, from the vitreous or colloidal into the crystalline...
Page 5 - The colloidal is, in fact, a dynamical state of matter ; the crystalloidal being the statical condition. The colloid possesses energia. It may be looked upon as the probable primary source of the force appearing in the phenomena of vitality. To the gradual manner in which colloidal changes take place (for they always demand time as an element), may the characteristic protraction of chemicoorganic changes also be referred.