Paving Brick and Paving Brick Clays of Illinois (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1908 Excerpt: ...substance in the secondary clays, save that of plasticity. Chemically alike, and differing physically only in this one respect, yet to the one, according to this theory, -must be accredited no, or very little, molecular attraction for water, and to the other a strong molecular attraction. Grout1 may be quoted as follows: "The attraction of two grains may vary with the nature of the grains. The greater the attraction the farther they can be separated without losing coherence.. Another way in which the films become viscous is the result of molecular attraction, which binds a film over the surface of the grain and renders it viscous. The friction between this film and the solid grain of clay is said to be infinite, compared with water outside of the film. But when forced to move, the resistance would depend on the strength of the attraction of clay and liquid., . The change in viscosity or i Jour. Am.Chem.Soc, Vol.XX VII, No.H, Sept.1905, p.1016. in thicknes of the film, seems to be beyond the region of experiment. The quantity is too small to admit the determination of slight changes, but such are constantly assumed in physical problems. W. J. A. Bliss speaks of clay particles and the surrounding adherentliquid as follows: 'The thickness of this shell depends on the intensity of the attraction between the solid and the liquid.' J. B. Mills says: 2Molecular attraction depends primarily on the chemical constitution of the molecule.--.' Certain rare organic colloids increase the plasticity by rendering the water viscous.. The tendency fpr tensile strength to vary with plasticity is also easily explained in this way. Molecular attraction between two kaolin grains may be high. If the attraction for water is high, some water will be drawn between the grains and ...