﻿Royal Society. 239 



addition, as a necessary part of that knowledge, an acquaintance 

 with the laws of the results of chemical action, which he will know 

 how to express intelligently either in simple or structural symbols. 

 He will also possess a cultivated observation, and he will not fail to 

 have become at once more logical and critical. Thus armed, he may 

 undertake the study of qualitative analysis with confidence. 



The second Part commences with an account of reagents and group 

 reagents. Of these, the former are given in detail under the respective 

 elements ; the latter precede them in their proper deductive order. In 

 the separation of mixtures, every effort appears to have been made to 

 adhere in the main to quantitative methods ; in this way the time of 

 both teacher and student is economized, and the latter is assured of 

 the precision of his operations. Basylous bodies are considered in 

 the first six chapters of the eight of which this division of the book 

 consists ; acid substances (organic and inorganic) are treated of in 

 the remainder. A scheme for the analysis of simple and complex 

 substances, both in the dry and wet way, forms a fitting sequel to 

 the whole : the Tables of which it consists are those of the Royal 

 College of Chemistry, where the author is chief laboratory instruc- 

 tor. These have been repeatedly revised and corrected, having been 

 made the basis of special inquiries during the course of several years ; 

 they are now published for the first time, and will be warmly wel- 

 comed by old collegians. The special feature of this book is, as we 

 have said, the introduction of the graphic method and its principles 

 into analytical training — not, therefore, as an end, but a means to an 

 end. Upon the atomic notions which underlie that method, the 

 author justly refuses to dogmatize. "Indeed," he says (p. 31), 

 "matter itself being as yet unknown to us, need w T e wonder that 

 the very existence, size, shape, &c. of the smallest particles of 

 matter should not be capable of experimental demonstration ? Where 

 experiment fails to throw light upon the absolute nature of the con- 

 stant chemical combining proportions, and can at best only supply 

 us with relative data, hypothesis steps in." We may agree or dis- 

 agree with the atomic hypothesis ; but in either case we must admit 

 the indebtedness of chemical literature to the writer. Mr. Valentin 

 teaches his student to reason — thereby enabling him to acquire, in 

 time, a power of independent judgment, both as to facts, to theories, 

 and the nature of theory. 



XXXI. Proceedings of Learned Societies. 



ROYAL SOCIETY, 



[Continued from p. 71.] 



Nov. 24, 1870.— General Sir Edward Sabine, K.C.B., President, in 



the Chair. 



THE following communication was read : — 

 " On the Theory of Resonance." By the Hon. J. W. Strutt. 

 An attempt is here made to establish a general theory of a certain 



