Page:Text-book of Electrochemistry.djvu/171

 156 CONDUCTIVITY OF ELECTROLYTES. chap. ix.

molecular weight of a pure colloid. It is very certain, as other investigations have also shown, that the molecular weights of these substances are very high.

It might appear strange that a force of 302 x 10^ kilograms is required to move a gram of hydrogen ion in water with a velocity of 1 cm. per second. However, it is known that the more finely divided a suspended substance is, the slower does it deposit under the influence of some force, eg. gravity (or rather the dijfference between the specific gravity of the suspended solid and that of the liquid). A good example of this is offered by the fat globules in milk. The ions being infinitely smaller than the particles of suspended matter, it is therefore not so astonishing that these move so slowly under the infiuence of tolerable forces.

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