She formed extensive geological collections illustrative of the fossils of the silurian rocks of the south of Scotland during the family's annual holidays at Girwen.
[3][1] In March 1874 Gray entered the service of the Bank of Scotland as superintendent of branches, Edinburgh, and eight years later he became cashier there, an appointment which he retained during the rest of his life.
[5][1] This society, one of the oldest scientific bodies in Edinburgh, had ‘fallen into one of its periodic fits of depression,’ when, in 1877, Gray accepted its secretaryship.
He entered on his duties with great energy, and, by his courtesy and singular charm of manner not less than by his power of organisation and his excellent business faculty, he was successful in introducing needed reforms, in attracting new members and inspiriting old ones, and, finally, in placing the society upon a satisfactory footing as an active scientific body, issuing printed ‘Proceedings.’ At the time of his death, which occurred suddenly in Edinburgh on 18 February 1887, Gray was engaged, in conjunction with William Evans, upon a volume dealing with the birds of the east coast of Scotland.
Their daughters, Mary, Alice, agnes and Edith were also known for creating fossil collections, most of which are now held by the Natural History Museum in London.