Priestley was well received in New York, many people meeting him on landing, and he was presented with addresses of welcome from various societies. After a stay of about a fortnight he proceeded to Philadelphia and received an address from the American Philosophical Society, and by a unanimous vote of the trustees was offered the Professorship of Chemistry in the University of Philadelphia.
In the following July, in order to escape from the heat of the city, he moved to Northumberland, a town about a hundred and thirty miles north-west of Philadelphia and situated at the confluence of the north-east and west branches of the Susquehanna, near to which place his eldest son, together with certain other persons, mainly Englishmen, projected a settlement. Priestley himself had no pecuniary interest, as has been stated, in the undertaking, and he was not consulted in its formation, nor had he even decided to join it if carried into effect. We learn from his son’s account that the scheme of settlement was not to be confined to any particular class or character of men, religious or political. It was set on foot to be, as it were, a rallying point for the English, who were at that period emigrating to America in great numbers, and who, it was thought, would be more happy in society of the kind they had been accustomed to than they would be if dispersed through the whole of the States.
Owing to disagreements among the projectors, the scheme of the settlement fell through. Priestley, however, who was charmed with the beauty of its situation and the nature of its surroundings, determined to settle at Northumberland. Although at that time remote from any considerable town it was obviously destined to become a great thoroughfare. It was apparently healthy and less enervating, at least in summer time, than Philadelphia. Living was cheaper there than in that city, and he would be more free from care and more at liberty to follow his own pursuits than if burdened with the responsibilities of teaching. Lastly, his poor wife, who had never recovered from the shock of the Birmingham riots, needed rest and quiet. On these grounds, therefore, he decided to decline the offer of the Professorship at Philadelphia, as well as an invitation to take charge of an Unitarian congregation at New York, and to spend his remaining days in peace and retirement on the beautiful spot he had chosen. The year before his death he was offered the principalship of the University of Pennsylvania in succession to Dr Euen, but this office also he declined.
On his first settling at Northumberland in 1795 he was mainly occupied with his theological and metaphysical studies. During this year he published the work which had occupied him during his voyage from England, his Fast and Farewell Sermons, some tracts in defence of Unitarianism, and the third part of his Letters to a Philosophical Unbeliever, in answer to Paine’s Age of Reason, and he continued his Church History from the Fall of the Western Empire to the Reformation. In the house he had first occupied, which was barely sufficient in size to contain the family, he had little opportunity or convenience for doing experimental work.
Still, he made some observations on the analysis of air, and continued his inquiries on the generation of air from water.
Having determined to make Northumberland his home, he proceeded to build a house more suitable to his needs and pursuits, and, as his letters of the period show, its planning and arrangement gave him much thought and greatly interested him.
The house, which still exists, is similar in character to many middle-class American houses built in the country, a plain substantial erection, covered with match-boarding and fitted with jalousies, and to the front a loggia or verandah. The laboratory is a small building to the side, partially shaded by a large, wide-spreading tree.
In the autumn of this year he lost his youngest son, Henry, a bright and intelligent youth, of whom he was remarkably fond. This loss greatly affected him, for he had hopes that the young man would follow him in his theological and philosophical pursuits, to which he had shown an inclination. The death of his son was even more profoundly felt by his wife, whose health and spirits now began rapidly to decline, and she too passed away a few months later.
“Through life,” says her son, “she had been truly a helpmeet for him; supporting him under all his trials and sufferings with a constancy and perseverance truly praiseworthy, and who, as he himself, in noting the event in his diary, justly observes, ‘was of a noble and generous mind, and cared much for others and little for herself through life.’”
At about this period he preached and printed another of his defences of Unitarianism and completed his Church History, and began the compilation of his last treatise in defence of phlogiston.