Noble-hearted, sympathetic Thomas E. Thorpe wrote:
If, too, as you draw up to the fire 'betwixt the gloaming and the mirk' of these dull, cold November days, and note the little blue flame playing round the red-hot coals, think kindly of Priestley, for he first told us of the nature of that flame when in the exile to which our forefathers drove him.
Right there, "the nature of the flame," is one thing Priestley did explain in America. He discovered carbon monoxide--not in England, but in "exile."[2] It may not be an epoch-making observation. There are not many such and those who make them are not legion in number. It was an interesting fact, with a very definite value, which has persisted through many succeeding decades and is so matter-of-fact that rarely does one arise to ask who first discovered this simple oxide of carbon.
Priestley was a man of strong human sympathies. He loved to mingle with men and exchange thoughts. Furthermore, Priestley was a minister--a preacher. He was ordained while at Warrington, and gloried in the fact that he was a Dissenting Minister. It was not his devotion to science which sent him "into exile." His advanced thought along political and religious lines, his unequivocal utterances on such subjects,--proved to be the rock upon which he shipwrecked. It has been said--
By some strange irony of fate this man, who was by nature one of the most peaceable and peace-loving of men, singularly calm and dispassionate, not prone to disputation or given to wrangling, acquired the reputation of being perhaps the most cantankerous man of his time....
There is a wide-spread impression that Priestley was a chemist. This is the answer which invariably comes from the lips of students upon being interrogated concerning him. The truth is that Priestley's attention was only turned to chemistry when in the thirties by Matthew Turner, who lectured on this subject in the Warrington Academy in which Priestley labored as a teacher. So he was rather advanced in life before the science he enriched was revealed to him in the experimental way. Let it again be declared, he was a teacher. His thoughts were mostly those of a teacher. Education occupied him. He wrote upon it. The old Warrington Academy was a "hot-bed of liberal dissent," and there were few subjects upon which he did not publicly declare himself as a dissenter.