[1] He is primarily known for his books on algebra and his studies of seiches (wave patterns in large inland bodies of water) which earned him a Gold Medal from the Royal Society of London that was confirmed shortly after his death.

[2] He was born in Old Meldrum on 8 March 1851, the son of Margaret (née Burr) and William Chrystal, a wealthy farmer and grain merchant.

He graduated Second Wrangler in 1875, joint with William Burnside, and was elected a fellow of Corpus Christi.

He was elected a Fellow of the Royal Society of Edinburgh in 1880, his proposers including James Clerk Maxwell.

[10] He grew ill in 1909 and this worsened early in 1911, leading the University to grant him leave of absence from April of that year.