462 Proceedings of the Royal Society 
In 1860 he became acquainted with Sir David Brewster, having 
met him at his daughter-in-law Mrs Macpherson’s house in Lass- 
wade, and an intimacy and friendship sprung up between them, 
remarkable in several respects, and particularly in this, that young 
Deas was then barely one-and-twenty, while Sir David was in his 
eightieth year. The friendship thus formed subsisted during their 
joint lives, and was, I believe, a source of great pleasure and satis- 
faction to both, and certainly of great benefit to the younger of the 
two, though I venture to think that the benefit was mutual, as no 
one, and not certainly a man of Sir David’s years and peculiar 
character, could fail to derive advantage from the simple and sincere 
affection of a youth so amiable and intelligent as Mr Deas. 
Sir David said of him from the first, that he had a more thorough 
and a more comprehensive hold of scientific principles than any 
man of his acquaintance not professionally scientific, and that he 
had so rare a combination of the faculties necessary for scientific 
research, that he (Sir David) deeply regretted “ he was crippled by 
a profession so jealous as the law.” Of the intimacy that thus 
arose very pleasing traces are to be found in the interesting volume 
of Sir David’s Home life, by his daughter. In 1866 Sir David 
was seized when at Belleville with an unseasonable attack of hoop- 
ing cough, and his illness was so severe as to excite the greatest 
alarm in Lady Brewster and his friends, although his mind re- 
mained bright, clear, and active. “ A favourite young scientific 
friend,” Mrs Gordon states, “ Mr Francis Deas, was staying in the 
house at the time, and after hours of fatigue and suffering it was 
positive enjoyment to the invalid to make the little preparations for 
his visit, which was quite the event of the day. Believing himself 
a fast dying man, he left many instructions with Mr Deas as to 
the arrangement of his scientific instruments, &c., and two years 
afterwards, when the call really came, it was to this gentleman 
that he confided the finishing and reading of a paper for the Royal 
Society, which weakness prevented him from completing. It was 
on the Motion, Equilibrium, and Forms of Liquid Films.” 
Mrs Gordon gives us at the same time an interesting letter, 
written by Mr Deas to Mrs Macpherson after Sir David’s death, 
sending his reminiscences of the three weeks spent by them to- 
gether at Belleville on the occasion above referred to, and in a letter 
