QUESTIONS REQUIRING ANSWERS.

189. Illustrate by appropriate quotations the following remark:-"There are various passages of the Old Testament capable of a twofold application, being directly applicable to circumstances then past or present, and indirectly to others which Divine Providence was about to develop under a future dispensation."-J. B. M'C.

190. I am desirous of becoming acquainted with the works of our best poets, and should be glad for any suggestions from your literary correspondents as to the order in which they should be taken up, and any other remarks conducive to their more profitable study.-SEPTIMUS.

191. I shall feel greatly obliged by any of the readers of the British Controversialist informing me through its medium what books are sufficient to be read in order to obtain a first, second, and third class government certificate. Also, I wish to have pointed out some good pronouncing gazetteers of the world, with their prices, and remarks on each.-R. T.

192. Will any of your numerous correspondents be kind enough to furnish me, through the medium of your valuable magazine, with a list of books on architecture and civil engineering, and the name of a good magazine devoted to architecture and civil engineering, with the publisher's name and its price?-W. D.

193. In Mr. Carlyle's admirable pamphlet on the "Nigger Question," referring to Jamaica, he says (page 40), "that a bit of the life that was Oliver Cromwell's was laid there." We are not aware of either the Protector, or any of his connexions or descendants, having been personally in that island. Can any of our readers inform us-1. Whether the allusion is metaphorical or not; 2. Whether there are any descendants of the Protector still alive; and if so, who these are? We believe that the Rev. Dr. Cromwell, Presbyterian minister, London, and author of a work on Shakspere just published, claims such descent, though on what grounds we cannot say; and we remember of a reference made in the biography of some divine either to the same gentleman or some other clergyman of the same persuasion, as being a descendant of Oliver Cromwell. We shall feel obliged by being informed, moreover, how the controversy raised two or three years ago regarding the erection of a statue of Cromwell among those of the kings of England in the new houses of parliament was concluded.-T. U., Edinburgh.

ANSWERS TO QUESTIONS.

150. Foreign Exchanges.-Not having seen the articles on this subject which W. U. says appeared in the Economist for 1847, we did not attempt to answer his inquiry respecting the science of foreign exchanges, and the illustratious there given of it. However, as no other friend has come forward, we beg to offer the following hints on the subject, which are extracted principally from M'Culloch's "Dictionary of Commerce:"

The term exchange is used to designate that species of mercantile transactions by which the debts of individuals at a distance from their creditors are cancelled without the transmission of money.

Among countries having much intercourse together, the debts mutually due by each other frequently approach near to an equality. For example, there are at all times a considerable number of persons in London indebted to Hamburgh, and vice versa. Hence: when A. of London, has a payment to make to B, of Hamburgh, he buys a bill upon Hamburgh, that is, he buys an order from C, of London, addressed to his debtor, D, of Hamburgh, request ing him to pay the amount to A, or his order. A, having indorsed this bill, or order, sends it to B, who, to his convenience, receives payment from his neighbour, D. Bills drawn by the merchants of one country upon another are termed foreign bills of exchange, and it is to their negouston that the following remarks apply:

1. Par of Exchange.-This, in the words of Fortune," signifies the equibalance of a certain amount of the standard currency of the one country in the standard currency of the other." Thus, according to the mint regulations of Grest Britain and France, £1 sterling is equal to 25 francs 20 cents, which is said to be the par between London and Paris. So, when a bill for £100, drawn on London, is worth 2,520 francs, and conversely, the exchange is said to be at par. When £100 in London buys a bill in Paris for more than 2,520 francs, the exchange is said to be in favour of London, and against Paris, and vice versa.

2. Circumstances which determine the Course of Exchange.-The exchange is made to diverge from par-first, by any discrepancy between the actual weight or fineness of the coins, or of the bullion for which the substitutes used in their place will exchange, and their weight or fineness as fixed by the miut regulations; and, secor.d.ỹ, by any sudden increase or diminution of the bills drawn in one country upon another.

We need not supply illustrations of these principles, but we would refer your correspondent for further information to Mr. M'Culloch s valuable work.-A. C.

170. Phenomena of Light.-Though I cannot furnish J. S. with the desired information, I may, perhaps, be allowed to say that there can be no difficulty in accounting for the appearances be describes. They present exactly the same aspect in a strong wind as in a calm; hence (setting aside the manifest improbability of the bypothesis the molecules he refers to are not particles of air. J. S. supposes them to be dust floating in the atmosphere: this also I think very unlikely, for, if such were the case, ought they not to be opaque? I have tried J. S.'s experiment, and beg to suggest as the result that the appearances are merely the secretion on the surface of the eye, and that it is a delusion when apparently we perceive them on the opposite side of the card, which serves the purpose merely of admitting light. I offer this merely as a suggestion. How

conformable it is to the laws of optics I know not. Perhaps some of your scientific friends will step forward and say. That it is moisture of some sort I have no doubt; but whether it may be accounted for as I have pointed out, or to a gathering of particles of fluid round the aperture in the card, I leave those who know more of optics than myself to judge. Persons who have weak sight, among whom, unfortunately, I must reckon myself, frequently observe the same phenomenon without having recourse to the means mentioned by J. S., especially when the weather is gloomy or the eyes have been tried by continued reading or study, by the sun or wind.Uris.

For the information of J. S., and those readers of this magazine who are interested in the subject to which his question refers, I may be permitted to state that the Frenchman who professed to have discovered the visibility of the component particles of the air was M. Andraud, and that some time since he made a communication of his suppositional discovery to the Académie des Sciences of Paris. J. S.'s description of M. Andraud's experiment is correct, but the following is more full-Take a card in which a very small aperture has been made, and hold it at the distance of one or two inches from the eye, and the following appearances will be visible-" 1st. The minute hole, of whatever figure it be, assumes the aspect of a perfectly circular disc. 2nd. This luminous dise, viewed as if it were an object at the usual distance of distinct vision, appears traversed by a fibrous or reticulated texture, interspersed with small specks or spots, some darker, some lighter, than the general tone of the disc. 3rd. Whatever number of these apertures are applied successively to the same eye, the configuration or pattern of this texture is always identical; but on changing the eye, though the general appearance remains analogous, the pattern becomes entirely different. 4th. Besides these appearances, minute globules are occasionally seen to move across the disc. On half closing the eye, the eyelashes become distinctly visible, so that they may be counted. Minute particles of dust on a plate of glass interposed between the eye and the aperture, with other similar objects, are readily aud distinctly perceived."

Now, from the identity of pattern presented successively to the same eye by any number of these apertures, it appears evident that it is something belonging to the structural condition of the eye that is thus seen, and not particles of air, as M. Andraud supposes. Indeed, the visibility of the texture of the eye itself of the minute globules of the lachrymal fluid on its surface

possibly even of particles of dirt slowly floating in the neighbourhood of the pupil, seem quite sufficient to account for the phenomenon.-A. C. 173. The Paraphrase of Paradise Lost.-It appears to us that your correspondent, G. N., has made a mistake in his paraphrase of the quotation made by "Stanislaus.' "O'Dell's interpretation is much preferable, but we think he also has fallen into a slight error. The only part of the quotation at all difficult to understand is the passage "Easier to transact with me

That thou shouldst hope, imperious, and with threats

To chase me hence."

Now, G. N. has departed very widely from the words and meaning of the original, and has read the passage as though Satan's indignant interrogation stopped at the word " unvanquished." He has also altogether lost sight of the words "easier to transact with me," and has treated the line which follows them as though "err not" had reference to, and should be taken before, it. These are altogether mistakes. Satan puts two questions. First, he asks Michael whether he has put the least-weakest-of these his hosts to flight; or, if he have smitten them to the ground, it was but that they might rise again unvanquisbed." Now, with simply a comma after the word unvanquished, as is the case in some editions of Milton, it would at first sight appear as though the word easier referred to the unvanquished host, and you might read the passage thus: "But that they might rise again unvanquished, the better, more determined,-to transact-perform deeds-fight-with me;" and, were there a comma after the word me, we should be inclined to put this interpretation upon it, and make the remainder of the passage-" that thou shouldst hope, imperious and with threats, to chase me hence," have reference to the one interrogatory with regard to having "put the least of these to flight." But there is no such stop after the word “me," and consequently a second interrogation is commenced at the word "easier," and is, in fact, the very point of Satan's argument. "Is it easier," he asks, "to deal with-manage-me (than it was to deal with the least of his followers, understood), "that you should hope, O imperious being" (or, imperiously, the adjective put for the adverb, as is often the case in Latin authors), "and, above all thes, with threats, to chase me hence?"

Such we think to be the correct reading of the passage. "Odell" has put a second question at the word "easier," but in our opinion it is a wrong one.-F. F.

truths or innate ideas? How does the experienceorigin of knowledge affect the law of ratiocination? How can the law of syllogism be deduced from the principle of generalization? What important ends would, in the author's opinion, be gained, supposing the topics discussed in this paper were established?

Provectior.-Exercise No. X., Vol. II.