WOLLASTON, WILLIAM HYDE. - CHEMICAL 'EQUIVALENTS' INTRODUCED.

A Synoptic Scale of Chemical Equivalents. Read November 4, 1813.

(London, W. Bulmer and Co., 1814). 4to. 4to. No wrappers as extracted from "Philosophical Transactions" 1814 - Part I. Pp. 1-22 and 1 engraved plate. Last textleaf slightly browned, otherwise clean and fine.

First appearance of this importent paper in which Wollaston introduces the "chemical slide rule".

"In 1814 he draw up "A Synoptic Table of Chemical Equivalents", wherein many "equivalents" (a term apparently first used in the chemical sense by him) were arranged in a logarithmic scale. Chemists found this device of great practical assistance, and it survives today in the form of the chemical slide rule." (A Source Book in Chemistry p. 221).

"The design of the scale here proposed by the author (Wollaston) is to save chemists the labour of many troublesome computations in estimating the ingredients of neutral salts, and the reagents and precipitates by whic these ingredients might be ascertained." (Abstract).

Order-nr.: 42248