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RAPHAEL EDUARD LIESEGANG 1869-1942 ERNST A. HAUSER Massachusetts Institute of Technology, Cambridge, Massachusetts
INTHE March, 1948, issue of THISJOURNAL I reported
the death of one of the greatest colloid chemists, Raphael Eduard Liesegang. The following short article, based upon information I recently received from his daughter, Maria, should give the reader some information about Raphael Eduard Liasegang which is known to very few; it deserves more general attention in honor of the memory of this great scientist. The fact that Raphael Eduard Liesegang was the discoverer of the periodic precipitation reactions in gels, now known as "Liesegang rings," and that he could look back on a long and very industrious life during which he offered to the scientific world with the vision of a genius many discoveries, surprises, and inspirations, was not his most outstanding characteristic. The most outstanding thing about this man was the unsurpassed devotion to science throughout his life which culminated in his belief in the unity of the living, the environment, and the entire cosmos. Early in his youth he laid the foundation for his philosphy in his first book, "Die Organologie," published in 1892, from which I would like to quote the following passage: "The trend toward a unified physical appreciation of nature can already be found over two thousand years ago as the basis of natural science of the ionic philosophers. I t culminates in an attempt to find a law which is valid for all branches of scienre and can alone explain all facts. First I shall attempt to find this axiom for the organology. In the next volume I shall attempt the same for the inorganology, and finally I shall attempt to eliminate the dualism between organic and inorganic." I t is worth while to remember that Liesegang made this statement fifty-six years ago and therefore certainly deserves credit for having been the first to break down the harrier between organic and inorganic chemistry in growing ernhryo of the silver germ is formed by the the range of colloidal dimensions. Another proof that Liesegang was far ahead of his developer. Very few people intlcerl are aware of the fact that it times in many special fields is his theoretical and experimental contributions to photography. Probably was Raphael Ednanl Liesegmg who had already pubone of his most cJassic expressions can be found in one lished in 1891 a book entitled, "Contributions to the of his earliest publications, when he refers to the Problem of Electrical Television." Not only did he "birth of silver," a t a time when analogies between in- predict, on a sound theoretical basis, developments of organic and organic reactions were rarely mentioned. which we are so prou
