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by the fishermen of the Adriatic, from the tradition of its being the fish of St. Peter. It seems to me that the corruption of the above term is likely to have caused its present appellation of Jean Doré or John Dory. I am, Sir, &c. S. Bowdich, Jan. 1829.

The A'nodon rugosus of Swainson (Vol. I. p. 96.) is the Anodónta marginata of Say. The latter described a specimen not full-grown, while Swainson's was an old one. You will remember Swainson expresses some surprise that it should have escaped Mr. Say's notice!! It is by no means uncommon in our rivers. J. L. Philadelphia, August 16. 1828.

Mr. Murray's Paper on the Aerial Spider.- Sir, The strong disinclination I feel to enter into discussions of a controversial character would, in all probability, have prevented me from noticing Mr. Murray's remarks upon my paper on the spiders which produce gossamer, had they been made in that spirit of fairness and candour which one gentleman is entitled to expect from another; the unhandsome manner, however, in which this writer has conducted his attack (for he has endeavoured to misrepresent my views), renders it imperative upon me to offer a few observations in reply. After stating that my opinions relative to the ascent of spiders into the atmosphere do not possess much force, Mr. Murray proceeds thus: - "It does not appear that this author had seen an account of my experimental researches on the ascent of the little aëronaut; otherwise, he might have hesitated in committing himself to the Linnean Society, in the view he has endeavoured to sustain, but which, however, I believe, is not new.

"M. Gay Lussac having found that soap-bubbles would not ascend in a room, though their ascent is rapid in the open air, unhesitatingly ascribes their ascent to warm currents emanating from the surface of the ground; rooted in this opinion, Mr. Blackwall concludes that the flight of the spider originates in a similar cause."

Now, in supposing that I had not seen his essay previously to submitting my own to the Linnean Society, Mr. Murray is completely mistaken. The truth is, I had read it with attention; but the perusal did not convince me that there existed the least necessity for retracting or even modifying a single opinion I have advanced. The term "committing," which Mr. Murray has employed in the passage cited above, to say the least of it, is uncourteous towards myself, and disrespectful towards the learned body alluded to, of which he is a member. With regard to the charge of want of originality, and of having borrowed my ideas from M. Gay Lussac, I may observe, that I was totally unacquainted with the experiments of that distinguished chemist upon soap-bubbles, and his mode of accounting for their ascent in the open air, prior to the publication of Mr. Murray's paper. The principle upon which I explain the ascent of the spiders which produce gossamer, I am well aware, has long been familiar to men of science. I make no pretensions whatever to the discovery of any new principle; but if the application of one already known, to the solution of an interesting and difficult problem in natural history, which, for more than a century, has exercised the ingenuity of speculative zoologists, entitle me to the claim of originality, I shall not withdraw it because Mr. Murray is pleased to insinuate that my view of the subject does not possess any novelty.

In direct opposition to the opinion I have advanced, Mr. Murray maintains that spiders have the power of propelling their lines, without any assistance from currents of air. "The aeronautic spider," he asserts, 66 can propel its threads both horizontally and vertically, and at all relative angles, in motionless air, and in an atmosphere agitated by winds; nay more, the aërial traveller can even dart its thread, to use a nautical phrase, in the 'wind's eye;'" and, further, he remarks that" these interesting aëronauts sometimes rise with the rapidity of an arrow in the zenith of the observer; at other times, they are seen to float parallel with the plane of the horizon; and, again, at variously inclined angles. Sometimes the ascent is extremely

slow. An ascending current of warm air, it is conceivable, might effect a vertical movement; but how it could push the insect along in the horizontal plane, is an enigma of more difficult solution."

The observations and experiments which have induced me to entertain the belief that currents of air are absolutely indispensable to the propulsion of those lines by means of which spiders accomplish their aërial journeys, and effect their transit from one distant object to another, are amply detailed in the Transactions of the Linnean Society, vol. xv. part ii.; so that persons interested in the investigation have an opportunity of forming their own judgment respecting them. I am not aware that any objection has been, or can be, urged against my experiments. To myself they appear perfectly conclusive; and I feel thoroughly convinced, that whoever may repeat them with sufficient care, will be satisfied that the results obtained admit of no other explanation than that which I have given.

For two years past I have been extending my observations, and multiply. ing and diversifying my experiments. The inferences deduced from them entirely corroborate my former opinions, and I might here bring them forward in their support; but as it is my intention to lay them before the public in a more complete form than I am at present prepared to do, I shall resist the temptation; nevertheless, I may state that my recent researches clearly establish the fact that spiders, when placed upon an upright twig whose base is immersed in water, although they make every effort in their power to effect an escape, are utterly incapable of darting out a line, even through a space of two inches, without the agency of air in motion; but that, when gently blown upon with the breath, most species emit their lines without difficulty.

The various directions in which spiders move through the atmosphere (sometimes in planes parallel to that of the horizon, at others in lines more or less inclined to that plane), Mr. Murray conceives there would be some difficulty in accounting for upon the principle of an ascending current of warm air. This opinion there is no disputing; but I do not perceive what it has to do with my theory of the ascent of these animals more than with Mr. Murray's electrical hypothesis. Unquestionably, a horizontal direction may be given by a current of air moving in that plane; a vertical one, by the ascent of air highly rarefied; and directions, intermediate between these two, will generally be regulated by the laws of compound forces. When the horizontal and vertical currents are equal in force, the line of direction will describe an angle of 45° nearly with the plane of the horizon; but when their forces are unequal, the angle formed with that plane will be greater or less according as one current or the other predominates.

Mr. Murray, after professing not to understand my meaning in what I say about the electricity of the atmosphere, proceeds to express his conviction that the atmosphere" is seldom or never in a neutral state with respect to electricity," as though he would induce a belief that I have attempted to support the opposite doctrine, whereas I have not so much as hinted at it. I have merely affirmed that spiders do not select those periods for making an ascent when "the electricity of the atmosphere is remarkable for its intensity." The language in which this fact is conveyed will not, I trust, be found deficient in perspicuity by the generality of readers; notwithstanding, if I knew how to render myself more intelligible to Mr. Murray's comprehension, I should be happy to do so.

From the many hundreds of experiments which Mr. Murray informs us he has made, the following is selected as decisive of the question upon which we are at issue: "I caught," says this author, "one of these aeronautic spiders a few days ago; the folding glass doors of the libraryroom leading into the garden were open, and the insect being conveniently arranged, it darted forth, from within the room, a lengthened thread diagonally upwards, and thus effected its ascent; a fact at complete antipodes

with Mr. Blackwall's opinion." Here, observe, not the least notice is taken of the temperature of the external air and the air within the room, neither does it appear that any means were resorted to for the purpose of ascertaining whether there existed an outward as well as an inward current of air; yet this, let it be remembered, is a specimen of the mode of investigation pursued by one who is solicitous to impress us with the idea that he has not "ventured beyond the pale of sound and sober reasoning, in the true spirit of inductive science."

Were I disposed to retaliate, I might now proceed to a critical examination of Mr. Murray's electrical hypothesis, but recrimination I shall avoid. My object is to defend myself from an unprovoked and illiberal attack, being sensible that the fallacy of all other doctrines must be made manifest by the establishment of my own.

In concluding, I may remark that if Mr. Murray had favoured us with a few more of his numerous experiments, instead of indulging in fanciful conjectures, he would have acted in stricter accordance with the spirit of that philosophy by which he professes to have regulated his enquiries. I am, Sir, &c. John Blackwall. Crumpsall Hall, Dec. 4. 1828. The Mallow of Horace. - Sir, I would speak under correction, but it appears to me that the elegant authoress of An Introductory View of the Linnæan System of Plants, in the last Number of your interesting Magazine, has not been fortunate in the selection of an example, to show that we are unable to identify many plants known to the ancients. She says: "The Mallow, so important as an esculent vegetable, and mentioned as such by Horace, and in the Old Testament, is now unknown. Most pro bably we have the plant, but are unable positively to identify it." - We may not be able positively to identify it; nor, from the imperfect knowledge of botany possessed by the early writers, can we positively identify more than a very few of the plants they have described: but, to say the least of it, in the case before us there is as much reason to suppose that the Malva of Horace is the same as the Mallow with us, as there is that it should be any other plant.

Miss Kent calls it an important esculent vegetable. But I think, that, neither by Horace, who mentions it upon two occasions *, nor by any other of the ancients, is it described as an important esculent vegetable. It was certainly used in the preparation of their food, but then it was in the same manner as we still use certain herbs as salutary with made dishes. Horace's description of the plant in this respect exactly corresponds with the qualities possessed by the genus Málva with us, at least with the natural order Malvàceæ, one genus of which, the Althæ'a officinalis, or Marsh Mallow, is still used in our Materia Medica as an emollient. I am happy to find that the late eminent botanist, Sir J. E. Smith, does not seem to have entertained any doubt of the identity of the ancient Málva with our own: speaking of Linnæus's natural order, Columníferæ, which is analogous to Jussieu's Malvàceæ, he says,t" This whole order contains no disagreeable or hurtful plant, nor are they esculent. None are fœtid, but some agreeably fragrant. Many of the flowers are beautiful. Their quality is generally mucilaginous, particularly Altha'a, Málva, and Alcèa. The ancients made considerable use of mallows in their food; but these plants are now out of use in that respect."

In the Old Testament mention is made of the Mallows only once ; and then not as if it were an important esculent vegetable,

* Epodon. od. 2. ver. 51. — et Od. lib. 1. od. 31. ver. 16.
+ Supplement to Encyclopædia Britannica, vol. ii. p. 406.
Job, chap. xxx. ver. 4.

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The patriarch Job is describing the former miserable lives of those who, in his affliction, had become his deriders; he says of them, "They cut up mallows by the bushes," &c. That is, such had been the wickedness of their lives, that they had been driven from society to dwell in caves of the earth, and were obliged to subsist upon roots and herbs, which were scarcely fitted to sustain life. That such is the meaning of the passage, appears from the marginal reference to Luke, chap. xv. v. 16., " And he would fain have filled his belly with the husks that the swine did eat." I am not, however, ignorant, that it has been doubted by many excellent commentators, whether the Hebrew word in the above passage from Job be rightly translated by our word Mallow: still I can see no reason why it should not be so. If there be, I should be very glad to be informed of it. The original word, according to Parkhurst, signifies an herb of a brackish or saltish taste." Now I would enquire whether some of this extensive order of plants will not answer the above description. You, Sir, will know whether any of the Mallows grow in Arabia, and if so, whether they may not be impregnated with saline particles. It may here be observed, that the Hebrew word is very similar in sound to the Latin word Malva, which we translate Mallow. What I have written is, I must confess, but little more than mere conjecture; and I shall be glad if any one of your numerous correspondents will strengthen my opinions. It is very important that the correctness of our venerable translation of the Bible should be called in question as seldom as possible, and certainly never unnecessarily so. The tendency to this evil has always been much too great: long ago, Bochart endeavoured to prove that the whale which swallowed up Jonah was a shark.* Dr. Adam Clarke has shown us that the serpent which tempted Eve was an ape; and many other fanciful opinions might be cited, which have been supported with more learning, I fear, than judgment.

To Miss Kent, I am sure, every reader of your Magazine, as well as myself, must feel obliged for the useful and interesting matter she has furnished us with. And if, on one point (which does not in the least call in question her knowledge of the subject before her), I have ventured to differ, she will, I hope, excuse me, when I assure her it is more with the wish of gaining information, than of expressing any confidence in my own opinion. I am, Sir, yours, &c.-G. M. Lynn Regis, Sept. 29. 1828.

Rhodiola millegràna (Vol. I. p. 437.) should be Radìola millegràna: it is a very different genus.-R. S.

The New Holland Anonaceous Plant (Vol. I. p. 438.) is proved by Mr. Brown, in the Appendix to Captain Tuckey's Voyage, not to belong to Anonàcee, and is therefore left out of Decandolle's Pródromus: it is a species of Cargillia.- R. S.

Geology of Palestine.-Sir, In your valuable Magazine of Natural History (Vol. I. p. 390.) I observe a notice of a paper on the geology of Palestine, in which it is stated that there are no volcanic rocks on the borders of the Dead Sea. Though these may not have been observed, yet there are traces of a volcanic neighbourhood in the sulphur found near the southern extremity of it, and in the hot springs and sulphur in the valley of Calirrhoe, near the north end; for a notice of which see the interesting Travels of Captains Irby and Mangles (printed for private distribution in 1825), p. 453. and 467., and at p.573. and 377. Distinct volcanoes, some miles south of the Dead Sea, are described and laid down in the map accom panying that work, which it is to be regretted that the authors do not publish. See also a curious dissertation on the Dead Sea in Dr. Daubeny's important work on volcanoes, p. 279. - W. C. T. Jan. 1829.

*So that the Rev. Dr. Scot's paper read before the Wernerian Society contained no new thing. — See Mag. Nat. Hist., Vol. I. p. 291.

The Granite, in Yorkshire, mentioned by your correspondent, L. E. O. (Vol. I. p. 596.), is certainly only in the form of large boulders, which are very numerous in the county of Durham and north of Yorkshire, having been carried by a strong current from the north-west. In the street at Darlington is a very large one, which the large flesh-coloured crystals of felspar it contains show to have travelled from the neighbourhood of Shap, in Westmoreland, where the same variety of granite appears in the mass. Many specimens of the same may be traced to the mouth of the Tees. For a valuable dissertation on the subject of gravel and boulders, I would refer your correspondent to Professor Buckland's Reliquiæ Diluviana.— W. C. T. Jan. 1829.

ART. X. Obituary.

CHARLES Peter Thunberg, M.D., Knight, F.R.S. L.S. &c., the successor of the younger Linnæus as Professor of Botany at Upsal, died on the 8th of August last, in the 85th year of his age; after having filled the botanical chair, during half a century, with indefatigable zeal. He had travelled over a great part of the world, for the purpose of extending his knowledge, and exploring nature.

Died, Nov. 24., aged 74 years, Mr. John Ashby, one of the Society of Friends, and a grocer and draper in Bungay for many years preceding his death. He commenced his career as a naturalist in entomology; but, however amusing the collecting of insects might be, the destroying them was too revolting for him to practise; and he then turned his attention to botany, a study which he pursued with ardour nearly to the time of his decease. In his earlier life he was acquainted with Mr. Curtis (author of the Flora Londinensis), Mr. Woodward, and other distinguished naturalists. He discovered many rare plants in this neighbourhood, to which his botanical rambles were principally confined; and he is mentioned in Smith's Flora Britannica and English Flora as the finder of the Ornithogalum lùteum at Shipmeadow, about three miles from this town. Mr. Ashby formed a herbarium of British plants, in which may be found not a few of the uncommon plants of this kingdom. He did not confine himself entirely to botanical pursuits, as he also formed a very excellent collection of coins; and his specimens of fossils, &c. are also rather numerous. Daniel Stock. Bungay, Feb. 4. 1829.

Died, Jan. 6., in his 79th year, Robert Stone, Esq. F.L.S., formerly an inhabitant of this town, but for the last twenty years he resided at Bedingham Hall, in Norfolk, the family estate. Mr. Stone was well known as a botanist. An ample testimony of his labours in the science of botany may be found by a reference to the early editions of Withering's Botanical Arrangement, in which Mr. Stone assisted, and in which his name so frequently occurs, that to particularise any instance would be quite useless. His herbarium of British plants is nearly complete. Having spoken of Mr. Stone as a naturalist, as a man what am I to say of him who was universally esteemed and respected by his friends and acquaintance? - Id.

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