In looking over Dr. Turner’s first and second sections on caloric and light, in the _Elements_ now before us, we find little but brevity to complain of;—there are, however, one or two trifling historical inaccuracies: thus, at page 14, the discovery of _invisible_ heating rays is ascribed to Saussure and Pictet; but it is, in fact, of much more remote origin—it was well known to the Florentine academicians, and we may even trace the idea in Lucretius, (_De Rerum Naturâ_, lib, v. 1, 609.) Forsitan et rosea Sol alte lampade lucens Possideat multum _cæcis fervoribus ignem_ Circum se, _nullo qui sit fulgore notatus, &c._ At page 31 we have an account of Wedgwood’s pyrometer, which is said to be “little employed at present, because its indications cannot be relied on;”—the fact is, that it is never used, and that we owe to Sir James Hall ample reasons for placing no confidence in it. The subject of _specific heat_ is clearly explained, and so are the phenomena of liquefaction and evaporation. In regard to the constitution of gases, the author remarks, that the experiments of Sir H. Davy and Mr. Faraday on the liquefaction of gaseous substances, appear to justify the opinion that gases are merely the vapours of extremely volatile liquids. Mr. Faraday has proved this in regard to several of the gases, and analogy leads us to apply it to the rest;—but what share Sir H. Davy had in the discovery, we know not; for Mr. Faraday actually condensed chlorine into a liquid before Sir H. had heard or thought about the matter. _Light_, and its phenomena as connected with chemistry, is superficially passed over in the second section, and the third brings us to the important article “Electricity.”