By this time too, it had been discovered, that there were other powers in nature that must be called in to explain appearances, which the mechanical and corpuscular philosophy had endeavoured to elucidate in vain. Such were magnetism, electricity and chemistry. It began to be found out, that the science of calculation, was but an aukward handmaid to their sister branches of natural philosophy, while physiology, laughed outright at the clumsy addresses of her mathematical admirers, from Borelli to Keill.
The discoveries therefore relating to light and colours, at the time when Dr. Priestley proposed his history, being intimately associated with the study of the mathematics, and the profound investigations of Sir Isaac Newton, were out of the beat of the less laborious, but more fashionable philosophy of the day; and were not so generally interesting to the Sciolists and Amateurs. Hence the work in question, though treated in a very entertaining and popular manner, and by no means crouded with reference to Diagrams or abstruse discussions, was not popular even among that class of readers, who might reasonably be calculated on, as the purchasers of such a performance. The subscribers indeed were sufficiently numerous, and respectable, but by far the majority were defaulters in respect of payment. It did not pay the bookseller: and of course still less did it recompence Dr. Priestley in a pecuniary point of view, especially as he had gone to considerable expence with a view to the completion of his extended plan. To him indeed, though pecuniary loss was a serious evil, pecuniary profit was a consideration of small importance: his motives to literary labour seem uniformly to have arranged themselves as follows, utility, reputation, profit.
The work in question is certainly too brief, considering the importance of the subject: many parts of it, the theory of Huygens, Euler, and Franklin for instance, seem to have merited more discussion. That all the phenomena of light depend on the Sun, as the reservoir, whence all the emanations of that fluid to the various parts of the system are supplied, the lighting of a candle is alone sufficient to refute. The facts discovered to us by modern Chemistry will suggest a great many other doubts of the doctrines respecting light, which were regarded as well established when Dr. Priestley’s book was written. But it was a faithful account of the knowledge of the day, and an unprejudiced tribute to the reputation of those philosophers who had from time to time extended the boundaries of science on the subjects treated of.
Not a little has been added to the mass of facts then published, by the subsequent experiments of Dr. Priestley himself, and his fellow labourers in the Chemistry of the Gasses: and notwithstanding the experiments of Sir Isaac Newton and his predecessors, the theory of light and colours is not yet rested upon facts sufficiently numerous, and decisive to satisfy the enquiries dictated by the present state of knowledge.
But with all these disadvantages, the work has nevertheless maintained its ground, for we have no where else so systematic, and compleat, though brief an account of what had been made known to the world on this important branch of scientific inquiry. It will always remain a valuable performance; and to the author an honourable one, from the knowledge and ability required in its compilation, from the fairness of the account it gives, and the entertaining statement of facts and suggestions interspersed through the book.
It is greatly indeed to be wished, that these histories should be continued on the plan which Dr. Priestley has adopted. So that all the prominent facts should be collected in the order of their discovery, and a full view be given of the ground already gone over. Abridgments, do not answer this purpose; the theories that dictated the experiments are not detailed, their truth or their fallacy cannot be judged of, and sufficient merit is not attributed to the labours of the discoverer, or the bearings of his facts on his theory, sufficiently explained. To attain gradually to the summit of the temple of science, we must not only build on the foundations of our predecessors, but know somewhat of their intentions at the time of laying them.
The minor treatises of Dr. Priestley on electricity, perspective and natural philosophy, have this discrimination of character, that they are more calculated to allure young people to the study of those subjects than almost any of the introductions which have either preceded or succeeded. Philosophy is made, not an abstruse science, but a delightful amusement. Indeed it was the fort of Dr. Priestley to make knowledge intelligible and popular, and treat it in such a way, as to invite rather than deter, those who were inclined to enter upon these delightful pursuits. The plainness and simplicity of his syllabus, the amusing complexion of the Phenomena, by which he illustrates his doctrines, and the facility with which the one can be made, and the other comprehended, affords a very useful example to those who may have the same object hereafter in view. This was doubtless, owing to his long experience as a teacher: and his success in that capacity among his pupils, with the electrical machine, and the air pump, is full evidence of the practical utility of his plans of instruction.
Catalogue of Dr. Priestley’s smaller pamphlets and uncollected papers on philosophical subjects.
| Nicholson’s Journal. new series. | |
| V. 1 p. 181. | Reply to Mr. Cruikshank’s. |
| Ibid 198. | Experiments on the Pile of Volta. |
| V. 2 p. 233. | On the conversion of iron into steel. |
| V. 3 p. 52. | On air from finery cinder and charcoal. |
| V. 4 p. 65. | Farther reply to Mr. Cruikshank’s. |
| Amer. Trans. | |
| V. 4 p. 1. | Experiments and observations relating to the analysis of atmospherical air. |
| V. 4 p. 11. | Farther experiments relating to the generation of air from water. |
| Ibid p. 382. | Appendix to the above articles. |
| Republished Ib. Vol. V. | p. 1. Experiments on the transmissionof acids and other liquors in the form of vapours over several substancesin a hot earthen tube. |
| p. 14. Experiments on the change ofplace in different kinds of airthrough several interposing substances. | |
| 21. Experiments relating to the absorption of air by water. | |
| 28. Miscellaneous experiments relating to the doctrine of phlogiston.together. | |
| 36. Experiments on the production of air by the freezing of water. | |
| 42. Experiments on air exposed toheat in metallic tubes. | |
| New-York Med. Repos. | Title and Date. |
| Vol. 1 p. 221. | Considerations on the doctrine of Phlog. and the Decomp. of water. (Pamphlet) 1796. |
| Ibid p. 541. | Part 2d of do. (Pamphlet 1797.) |
| Vol. 2 p. 48. | (Pamphlet) to Dr. Mitchell. |
| Ibid p. 163. | (Pamphlet) on Red Precipitate of Mercury as favourable to the doctrine of Phlogiston, July 20, 1798. |
| Ibid p. 263. | Experiments relating to the calces of metals communicated in a fifth letter to Dr. Mitchell. October 11, 1798. (Pamphlet.) |
| Ibid p. 269. | Of some experiments made with ivory black and also with diamonds. (Pamphlet) 11 October, 1798. |
| Ibid p. 383. | On the phlogistic theory, January 17, 1799. (Pamphlet.) |
| Ibid p. 388. | On the same subject. February 1, 1799. |
| Vol. 3 p. 116. | A reply to his antiphlogistian opponents, No. 1. |
| Vol. 4 p. 17. | Experiments on the production of air by the freezing of water. |
| Ibid p. 135. | Experiments on heating Manganese in inflammable air. |
| Ibid p. 247. | Some observations relating to the sense of hearing. |
| Vol. 5 p. 32. | Remarks on the work entitled “A brief history of epidemic and pestilential diseases,” May 4, 1801. |
| Ibid p. 125. | Some thoughts concerning dreams. |
| Ibid p. 264. | Miscellaneous observations relating to the doctrine of air, July 30, 1801. |
| Ibid p. 390. | A reply to Mr. Cruikshank’s observations in defence of the new system of chemistry, 5 Vol. Nicholson’s Journal p. 1, &c. |
| Vol. 6 p. 24. | Remarks on Mr. Cruikshank’s experiments upon finery cinder and charcoal. |
| Ibid p. 158. | Observations on the conversion of iron into steel. |
| Ibid p. 271. | Additional remarks on Mr. Cruikshank’s experiments on finery cinder and charcoal, November 15 1802. |