The progress of scientific chemistry in our own times : with biographical notices / by William A. Tilden.

  • William A. Tilden
Date:
1913
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Licence: Public Domain Mark

Credit: The progress of scientific chemistry in our own times : with biographical notices / by William A. Tilden. Source: Wellcome Collection.

    289/390 page 271
    « VIII] FREEZING POINTS OF SOLUTIONS 271 dissolved electrolytes, and the nature of solutions generally. So long ago as 1788 Sir Charles Blagden pub¬ lished in the Philosophical Transactions a paper dealing with the familiar fact that salt water does not freeze so easily as fresh water. In that paper he showed that various salts added to water cause a depression of the freezing point, and that the depression is in each case practically proportional to the amount of the salt present. There the ques¬ tion remained for nearly a century. The next steps in advance could only be taken when Blagden’s conclusions had been established upon a much firmer basis of exact experiment than he had been able to supply; and, as in so many other cases, it required the successive efforts of many experimenters to provide material upon which to build a theory with any prospect of success. Among the workers who took up the question must be mentioned Rudorff,1 De Coppet,2 and Guthrie.3 De Coppet got so far as to show that the “ co-efficient of de¬ pression” of the freezing point is constant for the same substance, and that it is equal for similar substances when added to the same quantity of water in amounts proportional to their molecular weights. It is, however, to the important researches of Professor F. M. Raoult4 of Grenoble that the 1 Pogg., cxiv. 63 (1861), cxvi. 55 (1862), &c. 2 Ann. Chim., xxiii. 366 (1871), xxv. 502 (1872), xxvi. 98 (1872). 3 Phil. Mag., 1875, 1876, 1878. 4 Ann, Chim., xxviii. 133 (1883), &c.
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