The Action of Silica on Electrolytes

Abstract

THE importance of this subject in chemistry and pedology is my excuse for a further letter in reply to that of Prof. Mukherjee in NATURE of October 9. I could wish that he had told us more as to the method by which he demonstrates primary adsorption, as until it is established—and this is the point of disagreement between us—it is scarcely worth while discussing its mechanism. I have now tried so many variations of the experiment in attempting without success to obtain Prof. Mukherjee's results, that I am a little discouraged, and this the more because the magnitude of the effects described in successive communications has been greatly reduced. Thus the early statement that considerable quantities of acids could be adsorbed by silica was modified by his letter in NATURE (January 31, 1925) stating that the silica used contained alkali. Again, in the issue of April 4, 1925, it was stated that 10 grams silica adsorbed 42 c.c. of decinormal hydrochloric acid, i.e. 250 × 10⁴ gram molecules of acid per gram molecule of silica. But in the letter under reply, this 250 has been reduced to 1.