Page:Proceedings of the Royal Society of London Vol 60.djvu/167

152 formation of the structure of a metal, at a temperature so far below its melting point, and, in the case of the gold-antimony and goldaluminium series, far below the melting point of the eutectic alloys, in the presence of only two-tenths per cent, of a foreign body, is probably not an isolated fact, and appears to open a new field for research.

In the Bakerian Lecture for 1894 the authors gave an account of their work on the viscosity of over seventy liquids, and they discussed the interdependence of viscosity and chemical composition. In order to render the investigation more complete, they have now made measurements of the viscosity of (1) a number of esters or ethereal salts, and (2) of ethers, simple and compound—groups of liquids, which with the exception of ethyl ether, have not hitherto been studied by them. The physicochemical relationships previously established made such determinations of special’interest, for it was shown that one of the most striking of the various connexions traced between chemical constitution and viscosity was the influence exerted by oxygen according to the different modes in which it was assumed to be associated with other atoms in the molecule. The influence which could be ascribed to hydroxyl-oxygen differs to a most marked extent from that of carbonyl-oxygen, and it appeared that ether-oxygen, or oxygen linked to two carbon atoms, had also a value which differed considerably from oxygen in other conditions.

In the present paper the authors give the experimental values for the viscosity of the ten lowest fatty esters, carefully purified samples of which had been placed at their disposal by Professor Sydney Young. With the help of Mr. Barnett, B.Sc., Assoc. R.C.S., they have also investigated the viscosity of five fatty ethers. By the kindness of the Photometric Standards Committee they have also been enabled to make observations upon various samples of carefully prepared isopentane, and they have supplemented their former observations by a new series of experiments upon ethylbenzene, for a sample of which they are indebted to Dr. G. L. Moody, of the City and Guilds Central Institute.

The details of the observations are given in precisely the same manner as in the first paper, and formulae of the Slotte type showing