The “Napanee Cemetery” referred to in The Toronto Daily Mail clipping is the Riverside Cemetery. Lord Cecil’s remains were not disinterred and repatriated to England, but remained in Napanee. The stone marking the grave is engraved as follows:
Sacred to the Memory of Lord Adelbert Percy Cecil Late Rifle Brigade Youngest Son of the Second Marquis of Exeter Born July 18th, 1841 Died June 12th, 1889
'Lord Jesus Retrieve My Spirit'



LORD CECIL DROWNED HE ACCIDENTALLY FELL OUT OF A SAILING BOAT IN TH BAY OF QUINTE, ONT.
KINGSTON,
June 13, 1889 – Lord Adelbert Perry Cecil, the evangelist, was drowned on Wednesday afternoon in the Bay of Quinte, near Adolphustown, about six miles east of Picton Ont., while sailing in company with Mr. Churchill from Belleville to Adolphustown with camp supplies. It appears from a dispatch I just received that when off Poole’s Point, a short distance from Adolphustown Wharf, His Lordship rose to adjust the sail, when, losing his hold, he fell headlong into the water. Coming up at some distance he swam around for a few minutes and then sank before the boat could be got around to where he was. As he was supposed to be a good swimmer it was thought he might reach shore safely or at least keep afloat until rescued. Mr. Poole who witnessed the accident from the shore, shouted to him to keep swimming for a few moments and he would be rescued. He shouted back “No!” and sank immediately. His body is now at Parker Allen’s Adolphustown and will probably be shipped to England. His friends in England have been notified. Lord Cecil was a guest of Parker Allen yesterday. Mr. Allen is an old united empire loyalist. His Lordship had spent the winter in the Southern States and came here in the spring. He was not in good health. Se spent much time, talent and wealth in propagating the Plymouth Brethren’s doctrine. He was eloquent, unassuming, devoted and, above all, generous. It was his intention to have returned to England this year. He had been in Canada since 18??, having come here with the First Rifle brigade in 18?? He was converted in Hamilton while on a march and he afterward resigned his commission because the War Office refused to allow him to preach the doctrine he professed to the men of his regiment. He was born on July 18, 1841, and at one time was a lieutenant of the First Rifle brigade. He was a brother of the present Earl and Marquis of Exeter, once known as Lord Burghley. The family seat is Burghley, near Stamford, Northamptonshire. Lord Salisbury belongs to a distantly connected branch of the same family.

Above notice From:New York Herald June 14, 1889

KINGSTON NEWS. INTERNMENT OF LORD CECIL AT NAPANEE CEMETERY. At the Request of His English Friends – Simple Ceremonies in Accordance with the Ideas of the Brethren
-From Our Own Correspondent. KINSTON, June 17, -- After the recovery of the body of Lord Cecil, it was placed in a heavy oak casket lined with metal and taken to the residence of Mr. Alexander Smith, manage of the Merchants’ Bank, Napanee, a warm personal friend of the deceased for years. Meantime a cablegram was sent to his friends in England, announcing the death and inquiring what disposal they desired should be made of the remains. An answer was received requesting that a photograph be taken and forwarded to them at once, in order, it is supposed, that they might satisfy themselves there was no mistake. This request was at once complied with, and Mr. Richardson, Napanee, was successful in obtaining a good likeness which has been mailed. Notices were issued announcing that the funereal would take place from Mr. Smith’s residence on Saturday noon, and thence to Napanee cemetery vault. At the appointed time a large number assembled to pay the last tribute of respect to the memory of a gentleman held in high esteem for many years past for is singularly devoted Christian life and his kindly charitable acts to all to whom he could do good. There was a large procession of carriages of the leading residents of the town, as well as a number from long distances around. The Brethren, of which he was such a distinguished and devoted member, felt most keenly their irreparable loss. Representatives of that fraternity were present from Montreal, Ottawa, Picton, Belleville, and Adolphustown. Among these may be mentioned Mr. Van Koughnet, Indian Department, Ottawa, and his wife; Mr. McKinnon, Ottawa; Messrs. Critherford and Aird, Montreal; Mrs. Bakus, Mr. White, and others, Picton, and Mr. Heignhoe, Belleville, Revs A.B. Chambers, E.E. Howard, J.H. Peake, and J. Shorts were also among those present. Religious services were conducted at the house by the Brethren after their own method. Hymns were sung, Scripture portions were read, and very impressive addresses were given by Mr. Alexander Smith, Napanee, and Mr. Heignhoe, Belleville, both of whom had for years been associates in Christian work. Before the body was deposited in the vault a second cablegram was received from England requesting that the body be interred. There was a short consultation among the friends, and it was resolved to return again at four o’clock for the burial, which was done. It is understood that it has been so arranged that should the request yet come for the remains to be sent to England they can be disinterred and forwarded.
Taken from:The Toronto Daily Mail June 18, 1889

His parents were:
Lord Exeter married Isabella Poyntz, daughter of William Stephen Poyntz, on 12 May 1824. They had at least five children:

William Alleyne Cecil, 3rd Marquess of Exeter (1825–1895)
Colonel Lord Brownlow Thomas Montagu Cecil (1827–1905)
Lady Mary Frances Cecil (1832–1917), married Dudley Ryder, 3rd Earl of Harrowby
Lord Adalbert Percy Cecil (1841–1889), member of the Plymouth Brethren
Lady Victoria Cecil (1843–1932)
Lord Exeter died in January 1867, aged 71, and was succeeded in his titles by his eldest son William. The Marchioness of Exeter died in March 1879, aged 76.