He was an accomplished pianist and composer, although he never published any of his works.
Of his four daughters only one, who married the Russian pianist Gabrilowitch, survived him.
On the advice of this great pianist, he gave up his Edinburgh appointments, which had quite worn him out, and settled in Florence in order to compose.
Her sister, Maria Teresa Agnesi (1724-1780), a well-known Italian pianist and composer, was born at Milan in 1724.
His interest in music was indeed stimulated from 1862 onwards by his friendship with Balakirev, and from 1863 by his marriage with a lady who was an accomplished pianist; but in his earlier years he had been proficient both in playing the piano, violin, 'cello and other instruments, and also in composing; and during life he did his best to pursue his studies in both music and chemistry with equal enthusiasm.