The Church History is, I hope, by this time in the hands of the bookseller at Philadelphia, so that you will soon, if my directions have been attended to, receive a copy of the work which I have the honour to dedicate to you.

With the greatest respect and attachment, I am

Dear Sir, Yours sincerely, J. PRIESTLEY.

Dear Sir,

I take the liberty to send you _a second defence of my pamphlet about Socrates_, on the 16th page of which you will find that I have undertaken the task you were pleased to recommend to me. On giving more attention to it, I found, as the fox did with respect to the lion, that my apprehensions entirely vanished. Indeed, I have already accomplished a considerable part of the work, and in about a year from this time I hope to finish the whole, provided my health, which is very precarious, be continued in the state in which it now is. I directed a copy of the _tract on phlogiston_ to be sent to you from Philadelphia, and I shall order another, which, together with the inclosed papers, I shall be much obliged to you if you will convey to. Mr. Livingston. Please also to cast an eye over them yourself; and if you can with propriety promote my interest by any representation of yours, I am confident you will do it.

When you wrote to me at the commencement of your administration, you said "the only dark speck in our horizon is in Louisiana." By your excellent conduct it is now the brightest we have to look to.

Mr. Vaughan having applied to me for a copy of my Harmony of the Evangelists, which was not to be had in Philadelphia, and intimated that it was for you, my son, whose copy is more perfect than mine, begs the honour of your acceptance of it, as a mark of his high esteem, in which he has the hearty concurrence of

Dear Sir, Yours sincerely, J. PRIESTLEY.

Northumberland Dec. 12, 1803.

His European correspondents were informed that he was much engaged with religious matters. While his theological views were not received very graciously yet he found

some young men of a serious and inquisitive turn, who read my works, and are confirmed Unitarians.

In one of his communications to Lindsey, written in April 1800, he expresses himself in the following most interesting way relative to his scientific engagements. American men of science will welcome it: This is the message:

I send along with this an account of a course of experiments of as much importance as almost any that I have ever made. Please to shew it to Mr. Kirwan, and give it either to Mr. Nicholson for his journal, or to Mr. Phillips for his magazine, as you please. I was never more busy or more successful in this way, when I was in England; and I am very thankful to Providence for the means and the leisure for these pursuits, which next to theological studies, interest me the most. Indeed, there is a natural alliance between them, as there must be between the word and the works of G.o.d.

He was now at work apparently in his own little laboratory adjacent to his dwelling place. For more than a century this structure has remained practically as it was in the days of Priestley. In it he did remarkable things, in his judgment; thus refuting the general idea that after his arrival in America nothing of merit in the scientific direction was accomplished by him. The satisfactory results, mentioned to Lindsey, were embodied in a series of "Six Chemical Essays" which eventually found their way into the Transactions of the American Philosophical Society. It is a miscellany of observations. In it are recorded the results found on pa.s.sing the "vapour of spirit of nitre" over iron turnings, over copper, over perfect charcoal, charcoal of bones, melted lead, tin and bis.m.u.th; and there appears a note to the effect that in Papin's digester "a solution of caustic alkali, aided by heat, made a _liquor silic.u.m_ with pounded flint gla.s.s." There is also given a description of a pyrophorus obtained from iron and sulphur. More interesting, however, was the account of the change of place in different kinds of air, "through several interposing substances," in which Priestley recognized distinctly for the first time, the phenomena of gaseous diffusion. There are also references to the absorption of air by water, and of course, as one would expect from the Doctor, for it never failed, there is once more emphasized "certain facts pertaining to phlogiston." His friends were quite prepared for such statements. They thought of Joseph Priestley and involuntarily there arose the idea of phlogiston.

The little workshop or laboratory, in Northumberland, where these facts were gathered, will soon be removed to the Campus of Pennsylvania State College. It will be preserved with care and in it, it is hoped, will be gradually a.s.sembled everything to be found relating to the n.o.ble soul who once disclosed Nature's secrets in this simple primitive structure, which American chemists should ever cherish, and hold as a Mecca for all who would look back to the beginnings of chemical research in our beloved country.

How appropriate it would be could there be deposited in the little laboratory, the apparatus owned and used by Priestley, which at present const.i.tutes and for many years past has formed an attractive collection in d.i.c.kinson College, (Pa.) There would be the burning lens, the reflecting telescope, the refracting telescope (probably one of the first achromatic telescopes made), the air-gun, the orrery, and flasks with heavy ground necks, and heavy curved tubes with ground stoppers--all brought (to d.i.c.kinson) through the instrumentality of Thomas Cooper, "the greatest man in America in the powers of his mind and acquired information and that without a single exception" according to Thomas Jefferson.

And how the Library would add to the glory of the place, but, alas! it has been scattered far and wide, for in 1816, Thomas Dobson advertised the same for sale in a neatly printed pamphlet of 96 pages. In it were many scarce and valuable books. The appended prices ranged quite widely, reaching in one case the goodly sum of two hundred dollars!

And as future chemists visit this unique reminder of Dr. Priestley it should be remembered that on the piazza of the dwelling house there a.s.sembled August 1, 1874, a group of men who planned then and there for the organization of the present American Chemical Society.

The "Essays," previously mentioned, will be found intensely interesting but they are somewhat difficult to read because of their strange nomenclature. Here is Priestley's account of the method pursued by him to get nitrogen:

Pure phlogisticated air (nitrogen) may be procured in the easiest and surest manner by the use of iron only--To do this I fill phials with turnings of malleable iron, and having filled them with water, pour it out, to admit the air of the atmosphere, and in six or seven hours it will be diminished ... what remains of the air in the phials will be the purest phlogisticated air (nitrogen).

Among his contributions to the scientific periodicals of the times there was one relating to the sense of hearing. It is a curious story. One may properly ask whether the singular facts in it were not due to defects in Priestley's own organs of hearing. The paper did not arouse comment. It was so out of the ordinary experimental work which he was carrying forward with such genuine pleasure and intense vigour.

Strong appeals were steadily coming from English friends that he return.

While commenting on the pleasure he should have in seeing them he firmly declared that the step would not be wise. In short, despite all arguments he had determined to

remain where I am for life.

The prejudices against him were abating, although he said

that many things are against me; and though they do not _shake_ my faith, they _try_ it.

There had gathered a cla.s.s of fourteen young men about him in the Northumberland home. They had adopted his Unitarian ideas. To them he lectured regularly on theology and philosophy. Those must have been inspiring moments. It was in this wise that the aged philosopher felt he was doing good and was most useful. He said that it was

a pretty good cla.s.s of young men to lecture to.

Much time was given to his English correspondents. Them he advised of the rapid development of the States. He sent to some pictures of the country about him, and with much delight he referred to the fact that Jefferson, whom he ardently admired, was now, in the closing weeks of 1800, the President, and his a.s.sociate--Aaron Burr, Vice-President. He announced to English friends that the late administration, that of John Adams, was

almost universally reprobated.

Mr. Jefferson, he insisted, "will do nothing rashly,"

His being president may induce me to visit the federal city, and perhaps his seat in Virginia.

The seat of government, as may be inferred, had been removed to Washington from Philadelphia. But to the latter center, which still offered many attractions, Priestley journeyed for the third time early in 1801. He was not especially desirous of making this third visit, but as his son and daughter came down a distance of 130 miles on business, he determined to accompany them. True, Congress was no longer there, but there were many interesting people about with whom he had great pleasure. With Bishop White, who was most orthodox and whom he saw frequently, he enjoyed much "Christian and edifying conversation." John Andrews was another favorite. He was a violent Federalist and informed Priestley that the latter

had done them (the Federalists) more mischief than any other man,

yet these two n.o.ble spirits lived in amity, and Priestley several times announced that Dr. Andrews was a Unitarian, which is not the thought today in regard to the latter.

It was an eventful year--this year of 1801. Much that was unexpected happened. It brought joy and it brought sorrow.

Perhaps it would be just as well to note the scientific progress of the Doctor during this year, for he gave forth the statement that he had succeeded in producing air by freezing water. This production of air was one of his earlier ideas (p. 62), and now he wrote--

The harder the frost was the more air I procured.

Further, he announced that on heating manganese (dioxide) in inflammable air

no water is formed,

and what is rather astounding, he was certain that _azote_ consisted of hydrogen and oxygen.

To the _Medical Repository_, which he regarded highly, there was sent a rather thoughtful disquisition on dreams. In it the idea was expressed

that dreams have their seat in some region of the brain more deeply seated than that which is occupied by our waking thoughts.

A "Pile of Volta" had been sent out from England. It amused him and he studied it carefully when he was led to remark upon the theory of this curious process as follows:

The operation wholly depends on the calcination of the zinc, which suffers a great diminution in weight, while the silver is little affected, and all metals lose their phlogiston in calcination, therefore what remains of the zinc in metallic form in the pile and everything connected with that end of it, is supersaturated with phlogiston.

More need not be quoted. It was phlogiston and that only which occasioned the electric current. It may properly be added that in this connection he wrote:

It is said the inventor of the galvanic pile discovered the conducting power of charcoal, whereas it was one of my first observations in electricity, made in 1766.

Some additional attention to air was also given by him, and in so doing he reached the conclusion that

The diamond and charcoal of copper are, as nearly as possible, pure phlogiston.

One wonders how he could so persuade himself, for these bodies surely possessed weight. Why did he not rely more upon his balance?

With Woodhouse he discussed the product from pa.s.sing water over heated charcoal. He had been endeavoring to refute certain statements made by Cruikshank. There is no question but that he had carbon monoxide in hand, and had it as early as 1799, and that he had obtained it in several different ways. Observe this statement: