The next year, with his eldest son for his companion, he repaired again to London. While there, he writes thus to his niece, Miss Valentine, now Mrs. Glennie:
"London, 20th July, 1787.
"I am just returned from Windsor, where I passed three days. I went thither, partly to see some friends, but chiefly that I might pay my respects to the King and Queen. They both received me in the most gracious manner. I saw the King first on the terrace, where he knew me at first sight, and did me the honour to converse with me a considerable time. Next morning I saw him again at prayers in his chapel, where he was pleased to introduce me to the Queen, who inquired very kindly after my health; observed, that many years had passed since she saw me last; regretted the bad weather which I had met with at Windsor (for it rained incessantly,) which, said she, has made your friends see less of you than they wished; and, after some other conversation, her Majesty and the Princess Elizabeth, who attended her, made a slight courtesy, and stepped into the carriage that waited for them at the chapel door. The King remained with us for some time longer, and talked of various matters."
Our author then proceeded to visit Dr. Porteus at Hunton, and Mrs. Montagu at Sandleford, but was obliged to quit the latter place sooner than he had intended, on account of the illness of his son, who shewed symptoms of that consumptive complaint to which he afterwards fell a victim. For the sake of medical advice Beattie carried him back to the metropolis, and from thence, by very easy stages, to Aberdeen. Soon after his return to Scotland, the invalid improved so much in health that he was able to take upon him part of the management of the class of Moral Philosophy in the Marischal College, having been appointed in June of this year (when he was not quite nineteen) assistant professor to his father.
In 1790, Beattie put forth the first volume of his Elements of Moral Science; and superintended an edition of Addison's Periodical Papers, adding a few notes to Tickell's Life of that author, and to Johnson's Remarks on his Prose Writings. The second volume of the Transactions of the Royal Society of Edinburgh, published during this year, contains 'Remarks on some Passages of the Sixth Book of the Æneid,' from Beattie's pen.
He had now to suffer the dire bereavement which he had long foreseen, the loss of his eldest son, the object of his fondest affection. He thus informs the Duchess of Gordon of the melancholy event:
"Aberdeen, 1st December, 1790.
"Knowing with what kindness and condescension your grace takes an interest in every thing that concerns me and my little family, I take the liberty to inform you, that my son James is dead; that the last duties to him are now paid; and that I am endeavouring to return, with the little ability that is left me, and with entire submission to the will of Providence, to the ordinary business of life. I have lost one who was always a pleasing companion; but who, for the last five or six years, was one of the most entertaining and instructive companions that ever man was blest with: for his mind comprehended almost every science; he was a most attentive observer of life and manners; a master of classical learning; and he possessed an exuberance of wit and humour, a force of understanding, and a correctness and delicacy of taste, beyond any other person of his age I have ever known.
"He was taken ill in the night of the 30th of November, 1789; and from that time his decline commenced. It was long what physicians call a nervous atrophy; but towards the end of June, symptoms began to appear of the lungs being affected. Goats' milk, and afterwards asses' milk, were procured for him in abundance; and such exercise as he could bear, he regularly took; these means lengthened his days no doubt, and alleviated his sufferings, which indeed were not often severe: but, in spite of all that could be done, he grew weaker and weaker, and died the 19th of November, 1790, without complaint or pain, without even a groan or a sigh; retaining to the last moment the use of his rational faculties; indeed, from first to last, not one delirious word ever escaped him. He lived twenty-two years and thirteen days. Many weeks before it came, he saw death approaching, and he met it with such composure and pious resignation, as may no doubt be equalled, but cannot be surpassed.
"He has left many things in writing, serious and humorous, scientific and miscellaneous, prose and verse, Latin and English; but it will be a long time before I shall be able to harden my heart so far as to revise them."