 Later on, in 1949 Dickey reported the polymerization of sodium silicate in the presence of four different dyes (namely methyl, ethyl, n-propyl and n-butyl orange).The dyes were subsequently removed, and in rebinding experiments it was found that silica prepared in the presence of any of these "pattern molecules" would bind the pattern molecule in preference to the other three dyes.Shortly after this work had appeared, several research groups pursued the preparation of specific adsorbents using Dickey's method.