. Eighth International congress of applied chemistry : Washington and New York, September 4 to 13, 1912 ... -- . nd prac-tically all translatory movement. Fig. 8, illustrates the finalstage of agglutination or stage attained more rapidly by theaddition of a coagulant in larger proportion than that requiredto produce the stage illustrated in Figs. 6 & 7. There are nofree globules and no movement of any description and the condi-tion is the same as that shown in Figs. 4 & 5, except that theaggregates are not joined up in strings forming a network butare in isolated groups of irregular size and s
. Eighth International congress of applied chemistry : Washington and New York, September 4 to 13, 1912 ... -- . nd prac-tically all translatory movement. Fig. 8, illustrates the finalstage of agglutination or stage attained more rapidly by theaddition of a coagulant in larger proportion than that requiredto produce the stage illustrated in Figs. 6 & 7. There are nofree globules and no movement of any description and the condi-tion is the same as that shown in Figs. 4 & 5, except that theaggregates are not joined up in strings forming a network butare in isolated groups of irregular size and shape, correspondingwith a turbid liquor containing flocculent masses which rapidlyrise to the surface and cream, leaving a more or less turbidserum below. The process can be watched and details noted. 28 Original Communications: Eighth International [vol. The streaming of the globules starts in the form of a it proceeds the Brownian movement ceases and the aggre- 1 Fig. 7. gates form like islands and come to rest. Uncoagulated glob-ules continue to stream forwards, moving in paths around and. between the stationary aggregates. In front of the wave Brown-ian movement of the globules appears to cease before the actualstreaming reaches them. If the coagulation is excessively slowthere may be practically no streaming but loss of Brownian IX] Congress of Applied Chemistry 29 movement spreads very slowly across the slide and in placessmall aggregates appear to form. It is however possible by ad-justing the proportion of acetic acid keeping it well below whatis required for coagulation, to stop the Brownian movementwithout producing any formation of aggregates or coagulationwhatsoever. This is important, as Freundlich 1 has throwndoubt on a similar observation of Henris, who used a weaksolution of sodium chloride for this purpose, because it was notin agreement with current theories of colloidal chemistry. These observations yield a ready explanation of the creaming,termed by
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