Anomalous stratification of copper carbonate in agar gel

Abstract

During the periodic precipitation of copper carbonate in agar gel it is observed that the spacing law of Jablczynski is not obeyed if the rings have to occupy all the positions of the series. Instead, if it is assumed that there may be discontinuities in the observed pattern which indicate that the rings of corresponding orders might not have been formed, the geometric law is faithfully obeyed. These discontinuities disappear if thiourea is added as an impurity along with the inner electrolyte. For different pH values of gel the pattern splits up into a number of groups, each exhihibits a revert type Liesegang phenomenon in which the last group contains revert followed by direct ring. The Liesegang phenomenon of this system has been explained on the basis of coagulation theory.