H. BEHRENS

A serious source of error in all microchemical methods is the fact that slight differences in the conditions under which crystallization takes place may profoundly affect the form and appearance of the crystals produced during a reaction: the acidity or alkalinity needs to be controlled in a number of cases; the concentrations of test substances and/or reagents may be important; and there are the cases in which interfering ions must first be removed.  The microchemical tests published up to this point in our survey were full of these problems.  Furthermore, there were still several gaps in Klément and Rénard's collection of reactions, and Professor Streng's manual did not have a means for detecting cadmium or nickel.

Professor H. Behrens (Figure 14) at the Hochschule in Delft, Holland directed his efforts to removing the sources of error in the published tests, and introducing many new and elegant methods. In addition to rigorously testing all the older reactions and methods, he added the data he obtained on the reliability and limits of applicability of the tests, as well as appending his notes and cautions to his accounts of the various reactions.  He also added tests for the rarer elements that were only then being found to be more widely distributed in the earth's crust than was formerly supposed.  Behrens wrote articles on his microchemical methods in Dutch, German, and French.

click image to enlarge (166K) Figure 14. Professor H. Behrens. Portrait in McCrone Research Institute Museum.

Professor John W. Judd, of the Royal College of Science, London had been using microchemical methods for mineral identification in the Geological Laboratories of that institution.  He learned of them when he met Boricky while on a visit to Prague in 1875, two years before Boricky's monograph appeared.  Later, Professor H. Behrens decided to translate his own book on microchemical analysis into English, and asked Professor Judd for his cooperation in bringing out this new edition.  Thus far, there had been no books in English on this subject except for Wormley's treatise, which was devoted to poisons, and so Professor Judd did not hesitate to accede.  And, thus, in 1894, we see the publication in English of, A Manual of Microchemical Analysis [Behrens, H. (1894)], to which Professor Judd contributed an Introduction.  This is a very nice book to own - not absolutely necessary, because the tests will be in Chamot and Mason, but from an historical perspective, you may enjoy critical comments, such as (page 101), "Haushofer has tried to develop staining of gelatinous silica with fuchsine... into a microchemical test.  It is not of sufficient delicacy for this purpose; besides, the stain, recommended by me for specimens of rocks, is of no use for gelatinous silica suspended in a liquid."

Behrens ends the century with the 1899 publication of his Anleitung zur mikrochemischen Analyse, and will open the new century with still another work.

Meanwhile, in America, a young man, Émile Monnin Chamot, from Buffalo, New York, entered Cornell University in 1887, graduated with a B.S. in 1891, and qualified for the Ph.D. in 1897.  His interests were in toxicology and sanitary chemistry, and he had been introduced to the application of microscopy to chemistry by Professor George Caldwell, the first head of the Chemistry Department there.  As was customary at the time, Chamot then went abroad for post-doctoral work.  He spent a year at the University of Nancy training in toxicology with Mace, and in Delft studying inorganic qualitative analysis with Professor Behrens.  On his return to America, and as the century closes, Chamot initiated a series of papers on microchemical analysis that appeared in the Journal of Applied Microscopy, starting in 1899.

Before leaving the 19th century, it would be well to note that there were very important, parallel developments going on, such as Otto Lehmann’s introduction of hotstage methods, Michel-Lévy's interference color chart, advances in optical crystallography, and even other microchemical methods in botany and physiology (urinary sediments, etc.).