IV. ANALYTICAL CHEMISTRY.
No branch of chemical science has a more general interest for the public than that which relates to the determination of the materials of which bodies are composed, and the proportions in which they exist.
At the beginning of the century considerable progress had been made in this branch of knowledge by the researches of Boyle (1626–1691), Hoffmann, Margraff (1709–1780), Scheele and Bergmann (1735–1784). Berzelius, as has already been mentioned, had added a new and valuable factor to chemical analysis by the development of the blowpipe, and in the early part of the century mineral analysis was still further advanced by Klaproth (1743–1817), Rose (1798–1873), and many others.
No one man did so much to advance this branch of chemical science as Fresenius (1818–1897). He collated and proved all the proposed methods of analysis, both qualitative and quantitative, and out of a confused mass of material formed a logical system of procedure, which has proved invaluable to the progress of chemical science in all its branches.
The volumetric methods of analysis, which save so much time and labor without sacrificing accuracy, were developed by Gay-Lussac, Vauquelin (1763–1879), Mohr (1806–1879), Volhard, Sutton, Fehling, and Liebig.
The methods of gas analysis have been worked out chiefly by Bunsen, ably assisted by Winkler and Hempel.
The methods of determining the elementary bodies in organic compounds have been developed by Dumas, Liebig, Will, Varrentrap, and Kjeldahl, to the last of whom chemical analysis owes a debt of gratitude for the invention of a speedy and accurate method of determining nitrogen.
Not much less is the debt due to Gooch for the invention of the perforated platinum crucible, carrying an asbestos felt for securing precipitates by filtration, in a form suitable to ignition without further preparation.
WILLIAM CROOKES, F. R. S.