Published online by Cambridge University Press: 06 July 2012
Since its discovery by Dumas and Péligot in 1834, methyl-alcohol has been the subject of a great many researches, and as a result we have long had a perfectly certain knowledge of its atomic composition, and a very accurate knowledge of a great many of its reactions. Yet the physical properties of the substance CH4O have not yet been determined with a satisfactory degree of precision. At this we need not wonder. For the study of the transmutations of a species a very impure specimen may suffice, and a series of such studies may leave no doubt about the correct atomic formula of the species in question, and consequently also, if it is a volatile substance, about its perfect gas density. But no other physical properties can be determined otherwise than by direct experiments on a pure specimen. And pure methyl-alcohol is very difficult to obtain. In whatever reasonable sense we may take the word “pure,” as attached to the name of a chemical preparation, “pure” methyl-alcohol must be admitted to have been little more than a chemical fiction until Wöhler in 1852 discovered his well-known (oxalate) process for its extraction from wood-spirit.
page 513 note * Krämer, and Grodzki, (Berichte der Deutsclien Chem. Ges., 1876, p. 1928)CrossRefGoogle Scholar determined the vapour densities of synthetically prepared mixtures of methyl-alcohol with acetone or dimethyl-acetal, and arrived at the curious result that the densities of the mixtures differed from the calculated numbers. I have recalculated, the numbers from their own data, and arrived at values which agree quite closely with those demanded by theory, i.e., the assumption that the several vapours mix without contraction or expansion. Anybody who cares can easily satisfy himself that I am right. I am glad to avail myself of this opportunity for disinterring a piece of meritorious work which got lost by an unfortunate lapsus calami in the construction of a formula.—W. D.
page 515 note * We propose, for the convenience of the reader, to quote the results in this manner; at the time we had, of course, to go by the specific gravity as a mere index of strength.
page 518 note * Cherm. Soc. Jour., [2], vi. 477; Annal. d. Chem. u. Pharm., Suppl., vi. 313; Jahresb.f. 1868, p. 500.
page 526 note * By Rosetti's Table for the specific gravities of water. Our constants give +4°·1 as temperature of maximum density.