He bequeathed Ford Castle to his granddaughter, Lady Susannah Hussey Carpenter, the only surviving child of his favourite daughter Sarah, Lady Tyrconnel, whose marriage in 1805 to Henry de la Poer Beresford, 2nd Marquis of Waterford, brought it to that family, in whose possession it has continued nearly to the present day. Doddington, however, with Seaton-Delaval and other entailed estates, descended to his next brother, Edward Hussey-Delaval, the only survivor of that band of eight brothers on whom Doddington had been successively settled, and not one of whom left a son to succeed him. As a young man he had been a Fellow-Commoner, and afterwards a Fellow of Pembroke College, Cambridge. Here he was a contemporary and friend of the poet Gray, who makes frequent mention of him in his letters. Later he established himself in a house which he had built for himself on his own plan and designs on a piece of ground leased to him by the Crown in Parliament Place. Its site is now covered by the Houses of Parliament, but two views of it taken from opposite points, painted by his friend G. Arnold, A.R.A., now hang in the Library at Doddington, and show its gardens running down to the river-side, with Westminster Bridge in the near distance. Here he devoted himself to philosophical and chemical pursuits, being a Fellow of the Royal and other learned societies, both home and foreign, and gaining their gold medals and other honours by his various papers and treatises published in their Transactions, or as independent works. Late in life he had married, and had an only daughter. He was in his eightieth year when he succeeded to the family estates, and seems to have concentrated all his care and interest on Doddington, buying up, as far as possible, the reversionary interests of his sisters in it, so as to leave it to his wife and daughter. During the years 1809-12 the whole of the mullioned windows of the Hall were repaired by him, new stonework and glass being inserted where required. The Great Fishpond was laid out and its banks planted in 1811, and all the detached buildings in the Hall yard—laundry and brew-house, stable and coach-house—were rebuilt in 1814 and 1815. An expert was employed by him to survey and restore the woods, which Lord Delaval had so devastated that no timber could be supplied from the estate. Various articles of furniture, pictures, and ornaments were brought here from Seaton-Delaval. A survey and valuation of the estate made in 1812 states that the mansion-house and buildings are in excellent repair.