Abstract
THIS book is only intended to facilitate the calculation of the results of an ordinary organic analysis, and its title, therefore, is somewhat misleading. It is stated that “the tables have been carefully calculated and checked, they are therefore absolutely accurate.” After this statement, nothing is left to us but to see if they are likely to be useful. After careful consideration of this question we are compelled to give an unfavourable reply. If we have the analytical result that 0.1173 gr. of a substance gave 0.2869 gr. carbon dioxide, we can, in the ordinary course of things, by looking out the logarithm of 0.2869, adding the easily remembered logs, of 12/44 and of 100, and subtracting the log. of 0.1173, get the log. of the percentage. But according to the tables before us, we look out a number corresponding to 0.117 and 0.28. We then look again for a number corresponding to 0.118 and 0.28. We subtract the two numbers, multiply by 0.3 by means of another table, and subtract this result from the first number looked out. We next find a number corresponding to 0.117 and 0.69, divide by 100 and add this result, and thus, after four references to tables, two arithmetical operations in the head, one subtraction and one addition on paper, we get our percentage. Appeal to a chemist constantly engaged in organic analysis has only confirmed the view that these tables are unlikely to save time or to promote exactitude in the calculation of organic analyses.
Percentage Tables for Elementary Analysis.
By Leo F. Guttmann Pp. 43. (London: Whittaker and Co., 1904.) Price 3s. net.
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S., A. Percentage Tables for Elementary Analysis . Nature 71, 460 (1905). https://doi.org/10.1038/071460a0
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DOI: https://doi.org/10.1038/071460a0