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Eighth Month.-1. Overcast.

REMARKS.

2. Cloudy. 3. Rainy. 4. Fine. 5. Showery. 6. Fine: slight showers. 7. Showery. 8. Showery: fine. 9. Showery. 10. Rainy. 1. Cloudy. 12. Fine. 13. Fine. 14, 15. Cloudy. 16. Showery. 17, 18. Cloudy. 19. Showery. 20. Fine: a slight shower at noon. 21. Cloudy. 22. Rainy. 23. Cloudy. 24. Rainy morning. 25. Fine. 26. Rainy: some distant thunder at half-past nine, a.m. heavy rain. 27, 28, 29. Fine. 30. Fine morning: afternoon rainy. 31. Fine.

RESULTS.

Winds: N, 1, NE, 1; SE, 1; S, 1; SW, 9; W, 9; NW, 9.

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For 15 days, ending the 23d (moon south) .......... 29.944

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ANNALS

OF

PHILOSOPHY.

NOVEMBER, 1823.

ARTICLE I.

On some Anomalous Appearances occurring in the Thermoelectric Series. By the Rev. J. Cumming, MA. Professor of Chemistry in the University of Cambridge.

(To the Editor of the Annals of Philosophy.)

MY DEAR SIR,

Cambridge, Oct. 13, 1823.

IN forming the thermoelectric series, which you did me the favour to insert in your journal, the metallic wires were connected at one extremity, and then immersed in boiling mercury. On varying this experiment, I find some anomalous appearances which seem deserving of notice.

If one of the wires be iron, and they be heated by a spirit lamp, the deviation, in some cases, gradually attains a maximum, then returns through zero, and at a red heat assumes an opposite direction; resembling in this respect the deviations made by the alloy of antimony and bismuth mentioned in my first communication to you on this subject. These effects, the detail of which I have subjoined, took place when iron was connected with silver, copper, gold, zinc, and brass, but not with platina or lead, and I have not observed it in other cases where neither of the wires was of iron.

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If the experiment be made by dipping wires, not previously connected, in boiling mercury, the deviation in the first instance depends, in some cases, upon the order in which they are immersed. I have observed this appearance more especially when one of the wires is copper, zinc, or brass. The results

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Copper with platina or tin was positive, with iron negative in both cases.

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Zinc with platina or tin was positive in both cases.

Brass with gold

silver

tin.

Brass last; negative.

Gold last; positive slightly, then negative.

Brass last; negative.

Silver last; positive slightly, then negative.

Brass last; negative very slightly, then positive.

Tin last; positive.

Zinc was positive with platina, and negative with iron, in both

cases,

It is obvious that the abovementioned thermoelectric peculiarity of iron will affect its place in the series, which at a red heat will be at least above brass, though at low temperatures it is decidedly below plumbago.

In regard to the series itself, it is not, perhaps, very material, provided the order be correct, whether we consider bismuth as the most positive, and antimony as the most negative metal, or the contrary; but analogy with the galvanic series seems to make the last the preferable arrangement. In this case, which I have now adopted, antimony, heat, and bismuth, form a circuit similar to silver, acid, and zinc; the silver and antimony being the positive, and zinc and bismuth the negative poles. The corresponding thermoelectric and galvanic series will, therefore, be:

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In this thermoelectric series, I have corrected an error as to the place of silver, arising from the wire formerly used, and which had been purchased as pure silver, being, as I have since found, alloyed with copper. The other changes are unimportant, excepting the insertion of galena, which in whatever way I have tried it, appears more strongly negative even than bismuth. Believe me, my dear Sir, most truly yours, J. CUMMING,

ARTICLE II.

Remarks on the Identity of certain general Laws which have been lately observed to regulate the natural Distribution of Insects and Fungi. By W. S. Macleay, Esq. MA. FLS.*

THE naturalists of the present day have in one respect a peculiar claim to the appellation of disciples of Linnæus; inasmuch as they direct their chief attention to what this great master declared to be the end of all his immortal labours in botany. His admirable maxim, that the natural system is the "ultimus botanices finis," is now not only universally admitted, but on all sides acted upon. The natural system is in fact not only made the remote consequence, but the immediate aim, of every modern observation in natural history; the rule now being, to commence with supposing nothing known but what has actually been observed, and by comparing the affinities thus collected, to search after that knowledge of natural groups which in the old methods we started with supposing to be already acquired. They who formerly confined themselves to artificial systems, and neglected the above important maxim of Linnæus, have at least thereby lost much gratification, since, if there be nothing within the whole range of human science more worthy of profound meditation than the plan by which the Deity regulated the creation; so most assuredly no study is more calculated to administer pure and unmixed delight. Thus, for example, the satisfaction of the mere gazer at a collection of animals must evidently be inferior to that experienced by the comparative anatomist, who understands their respective structures. And again, the anatomist himself, on viewing a museum, can scarcely be so much gratified by the sight, as that naturalist who, not content with a bare and in some degree insulated knowledge of particular organizations, endeavours to comprehend how these harmonize with the rest of the creation. It is in this last mode alone, if I may so express myself, that the human mind can take, as far as its imperfect nature will permit, a view of the universe as it was originally designed. Nor ought any person to be deterred from commencing so delightful a pursuit, either by the supposed difficulty of the investigation, or by the extent of preparatory information which it necessarily requires; for truly has it been said, that he who questions his abilities to arrange the dissimilar parts of an extensive plan, or fears to be lost in a complicated system, may yet hope to adjust a few pages without perplexity.

Having such ideas both of the dignity of natural history and of the importance and feasibility of a more extended research

* From the Linnean Transactions for 1823, Part I.

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