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ELECTROKINETICS. -X?LLi' THE ELECTROVISCOVTS EFFECT. 111. IS 8-L 1 C T O G L O B C L I S S Y S T E I I S . -4s I N T E R P R E T 4 T I O K O F THE 3 I E . i S I S G O F Iodiuni ions are replaced by one calcicm ion in the colloid electrolyte, the degree of snelling of the calciuin gum aiahate must he less than that of the qociium gum arabate. Hence, n e find that the vijcoqity ot a calcium g u m aiabnte .elution is less than that of the e-sodium chloride, it vas found that n s the ionic strength as increased above 0.01, the straight line of the plot of l/vsp ?nagainst --__ departs from linearity, the rise in the curve being interpreted A(% - 170) as a decrease in the T isconietiicdly effective volume ot the colloid. The K + / C value.; io1 the t n o systems 8-lnctoglohulin and --odium gum arabate are compared. Those for d-lactoglobulin TI ere found t o be constant throughout the range of ionic strength--.p,otein concentration, and pH employed; those ror sodium gum arabate TT eie round to decrease with high ionic strengths. A theory is proposed t o eyilain the difference- between these two systems as representative of tn-o diqtinct classes of colloidg. ,&Lactoglobulin i? pictiired a i a qtrong, inteinally n ell knit micelle, incapable of changing either in size. or shape, under the relatively neak, osmotic forces of its gegenions; sodium gum arabate is pictured aq an internally weakly knit colloid, tiilly capable of uncleigoing large changes in size, or shape, under the relatively TT eali osmotic influence of its gegenions. REFERESC'ES (1) BRIGGS, D . R.:J. Piiys. C l i e ~ ~45, i . 866 (1941). (2) HASKISBOS, C. L.. .
