Collegium ...1907 - Leather |
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Page 379 - 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.
Page 379 - 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 379 - ... 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 condition (H. Rose). The colloidal is, in fact, a dynamical state of matter ; the crystalloidal being the statical condition.
Page 250 - ... being allowed to settle and treated with further portions of boiling water. After the whole of the soluble matter is dissolved the solution is treated similarly to that of a liquid extract. Solid tanning materials previously ground till they will pass through a sieve of 5 wires per cm.
Page 139 - Solubles." 4. Non-tannins. — The solution must be detannised by shaking with chromed hide-powder till no turbidity or opalescence can be produced in the clear solution by salted gelatin. The chromed powder must be added in one quantity equal to 6 to 6.5 grm.
Page 251 - ... filtrate repeatedly ; and at the same time to evaporate 50 cc of clear filtrate obtained by the method for which correction is required, when the difference between the residues will be the correction sought. Note. — It is obvious that an average correction must be obtained from at least 5 determinations.
Page 253 - In the case of tans it must be clearly stated in the report whether the calculation is on the sample with moisture as received, or upon some arbitrarily assumed percentage of water ; and in that of liquors whether the percentage given refers to weight, or to grm. per 100 cc ; and in both cases the specific gravity shall be reported.
Page 251 - The kaolin must be previously washed with 75 cc of the same liquor, which is allowed to stand 15 minutes and then poured off. Paper 605 has a special absorption for a yellow colouring matter often contained in sulphited extracts.
Page 250 - ... cm. deep in a beaker, placed in a good light on black glass or black glazed paper, must appear dark and free from opalescence when viewed from above. Any necessary mode of filtration may be employed, but if such filtration causes any appreciable loss when applied to a clear solution, a correction must be determined and applied as described in paragraph 6.
Page 249 - Sections 1 to 4 of the following statement may be regarded as conforming to the recommendations of the International Commission on Tannin Analysis, but that members of the International Association must work according to the detailed directions contained in Sections 5 to 8.