Thomas Beddoes to Erasmus Darwin, [?October or November 1788]
Dear Sir
I acknowledge with thankfulness the receipt of your box and letter, and your good offices with Mr Bennet. I shall be glad to be acquainted with your philosophical clerk, though considering the activity of that mind that rouses into action the powers of the people in and about Derby, I should not be surprized if philosophy should extend a step beyond the desk and reach the pulpit also. I have not analysed the tar of Colebrook-Dale, nor do I know how any light could spring from its analysis, at least any analysis to which I could subject it. Should its nature be compared with that from wood and coal? The oily products of these I know differ much at different periods of the process. The causticity of Lord Dundonald’s I imagine arises from an impregnation with volatile alkaline air; which I suppose is formed and not merely extricated during the process: perhaps also the marine acid and volatile alkali that appear in the form of sal ammoniac, are each formed by the heat of the operation; but nobody knows what marine acid is; though for my part I think it to be composed of the same materials as the nitrous, from Doctor Priestley’s last experiment, and also from Margraaf’s finding both the one and the other in the atmosphere; though I easily see they might have been raised in vapour.
I shall be glad to see your paper, but I must honestly confess that no part of your system pleases me. There are as clear proofs of coal having been stratified by a deposition from water as of any other substance, both in the impressions of your specimens and in the marine exuviæ of intervening strata. Your idea of the spontaneous heating of vegetables is certainly ingenious, and may seem to have some support from analogy; but in the history of peat and subterraneous wood, I see not any reason for believing that they produce much heat during their change to that state in which they are found; and still less in the relative position of clay and coal do I see how it can be imagined that the clay is the fixed part left behind in the distillation. I am moreover unwilling to derive sulphur in almost any case from vitriolic acid. It has most evidently, in most cases, been sublimed from what Dr Hutton calls the mineral regions; where I hardly suppose vitriolic acid to exist. As to the acid of flint, can its existence be admitted? Is it inferred from Scheele’s experiments? or the chrystalline appearance of siliceous earth? I design a paper for the Royal Society on the formation of flint, in which I hope to render it probable that it has been produced from subterraneous heat: but why flint should be found in its present position I cannot comprehend. Dr Hutton’s supposition of its having been injected into chalk and wood does not assist my comprehension; and yet such as it is, each piece has derived its form from a state of fusion.
In my speculations on the antient fortunes of the globe, no question oftener recurs than what is the depth of the stratified arrangement of the surface? Does it reach for instance, three or four miles? From Mitchell’s hypotheses, it ought to reach so far at least. I think it would be very practicable with the aid of our powerful modern machinery and the concurrence of our liberal and enlightened contemporaries, to explore this.
In the accounts of the Calabrian earthquakes, a vorticose motion is constantly mentioned. Is not this merely the wave-like motion? as a tree placed just before the wave will be tilted forwards, so just after the wave has passed, it will be thrown back. If this is not what they mean, I do not understand them; nor can I comprehend how a really vorticose motion can be produced.
Your’s respectfully,
Thomas Beddoes
Published: Stock, Appendix 6, pp. xxxviii–xxxix