xl Proceedings of Royal Society of Edinhurgh. 
important of these, read January 21, 1878, is on “Suspension, 
Solution, and Chemical Combination” (Proc. Roy. Soc. Edin., ix. 
pp. 537-541). His main conclusions are, that between suspension 
and chemical combination there is no break in the series of grades 
of solution ; that chemical combination, solution, and suspension 
differ only in degree ; and that the attraction of chemical affinity 
is not, in all cases at any rate, exhausted when a definite compound 
is formed, hut has sufficient power left to form solution or suspen- 
sion compounds. His latest paper, on the “ Laws of Solution” {Proc. 
Roy. Soc. Edin.., xiv. pp. 381-387), discusses the last conclusion from 
the point of heats of combination. The first and second conclu- 
sions form the main theme of a very recent paper on “ Solution and 
Pseudo-Solution” {Tiuns. Lond. Chem. Soc., 1892), by Messrs Picton 
and Linder, who seem to have been unacquainted with Mr Durham’s 
pioneer work. Other papers by Mr Durham on the same subject 
will be found in vols. xi., xiii., and xiv. of the Society’s Proceed- 
ings) also in the Chemical News (1878), in Brit. Assoc. Reports 
(1887), and in Nature (vol. xxxvi.). Working at a time when the 
modern electrolytic theory of solution was but dimly apprehended, 
Mr Durham was unable to develop his views to their full signi- 
ficance. We should, perhaps, regard them as a first statement of an 
important aspect of the modern theory. In regard to Mr Durham’s 
powers as a practical chemist. Professor Crum Brown writes : — 
“ When I was asked to report on the means of purifying the Gala 
Water, I selected Mr Durham as assistant in the practical work and 
analysis, my choice being very much determined by the character 
of the papers which he had communicated to the Society. In 
that and in other similar work in which I had the advantage 
of his assistance, I found his uniform care and accuracy of great 
service.” 
Mr Durham was the writer of the long series of scientific articles 
which appeared with fair regularity, week by week, in the Scotsman 
newspaper from October 4, 1886, to December 3, 1892. The more 
important of these were republished in hook form under the general 
title of Science in Plain Language (A. & C. Black, 1889-91). The 
first volume treats of “ Evolution, Antiquity of Man, Bacteria,” &c. ; 
the second of “Astronomy — Sun, Moon, Stars,” &c. ; and the 
third of “ Food, Physiology,” &c. These titles sufficiently indicate 
