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.

    184/390 page 166
    rational formulas are only formulae representing the reactions and not the constitution of a body; they are nothing more than expressions for the meta¬ morphoses of a body, and a comparison of different bodies, and are in nowise intended as an expression of the constitution, that is of the arrangement, of the atoms in the actual substance.” The reasons he goes on to express for this hesitating position are not quite satisfactory. Almost at the same time, however, another young chemist, A. S. Couper, in a paper which appeared in all the chief chemical journals, put forth inde¬ pendently quite similar views as to the peculiarities of the element carbon, and by using a system of graphic formulae had even gone a step further. Couper showed, in the course of his paper, that the quantity of carbon represented by C2 (C = 6) is never divided during chemical changes; hence he remarks: “ It is only consequent to write, with Gerhardt, C2 simply as C, it being understood that the equivalent of carbon is 12.” 1 In consequence of peculiar views of his own, however, he retains 0 = 8, and hence all his formulae contain 02, or 0...0 in place of 0, but otherwise they resemble modern structural formulae. As Couper’s graphic formulae are the first symbols of the kind, and are so remarkably like those in common use at the present day, they deserve to be kept in remembrance. One example will suffice; 1 A. S. Couper, “Sur une nouvelle theorie chimique” (Ann. Chim., 53, 469 ; Phil. Mag. [4], 16, 104).
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