Abstract
THIS is still another addition to the numerous manuals on chemical arithmetic, and the points wherein it differs from its predecessors are somewhat difficult to discover. Once more we have specific gravity observations in which corrections for temperature and air displacement are ignored; and although the author attempts to set right the prevalent misconception as to the meaning of density and specific gravity, it is questionable if he succeeds. According to him, specific gravity is always relative; it is the same magnitude as relative density. The use of absolute specific gravity—or, shortly, specific gravity with no temperatures of comparison attached—as denoting the weight of unit volume, is here overlooked. From a physical point of view, the definition of the absolute density of a gas as the mass of 11.16 litres is a needless complication. In ascertaining the percentage composition of a compound it is insisted that, first of all, the molecular weight must be calculated. The examples given to illustrate the rule include apatite, apophyllite, basic lead chromate, &c. The student is thus led to infer, here as elsewhere in the book, that the molecular weights of such bodies can be fixed.
Chemical Calculations.
By R. Lloyd Whiteley With a Preface by Prof. F. Clowes, D.Sc., F.I.C. (London: Longmans, Green, and Co., 1892.)
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Chemical Calculations. Nature 45, 604 (1892). https://doi.org/10.1038/045604b0
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DOI: https://doi.org/10.1038/045604b0