glass. How is this mystery effected? It is a secret which Mr. Daguerre succeeded in discovering, after years of research. Without being able to explain the nature of the substance with which Mr. Daguerre covers his plates of copper, on which the object is to trace itself, we may venture a conjecture as to the facts on which the discovery depends, and which must have suggested to the inventor the idea of making the experiment. These facts are no secret they are known to every body. Certain vegetable coloring substances, which impart the most beautiful colors, such as rose and cerulean blue, have the property of fading when exposed to the sun or to strong day light. By means of this property a desired result may be obtained. Supposing the color is more sensible to the effects of light than those which are used in dyeing, it will be readily understood how the light would affect it in proportion to its intensity. Thus an object placed in the same position with regard to our eye and to the camera-obscura, would imprint itself in the same manner in both. In the eye only, the effect is momentary — in the camera, it requires a certain time, say fifteen or twenty minutes, to become complete. Attempts have been before made to make use of the chloride of silver for a purpose similar to that which Mr. Daguerre has succeeded in attaining; but as this material is white, and blackens when exposed to the light, the images obtained, instead of being presented in relief, would be in intaglio. Afterwards the object designed would entirely disappear in the light, as will readily be conceived. By arresting the action of the light at a fixed point, the French painter has triumphed over an obstacle which might have seemed insurmountable. In that consists the beauty of his discovery.

Means of preventing Chimneys taking fire. - Davy's Safety Lamp, has suggested to some person in France, to make use of wire gauze, to prevent fires in chimneys - the experiment has proved perfectly successful. Three pieces of wire gauze are placed one above another, in the lower part of the chimney, which not only prevents the possibility of the chimney taking fire, but also entirely supersedes the necessity of sweeping or cleaning them in any way. The soot is caught upon the gauze, and must be swept off occasionally; nothing more is requisite to keep the chimneys in perfect order. Improvement in Gas Making. By passing the stream of gas, mixed with tar and steam, as it issues from the cucurbite, through cylinders of cast-iron containing plates of the same metal, strongly heated, all the tar is transformed into gas. The quantity is increased twenty-five per cent by this process.

The French savants have been occupied for some time upon experiments of great importance to commerce the production of indigo from the polygonum tinctorium. Agriculturists, botanists, chemists, orientalists, and dyers, have all interested themselves in these experiments. The plant was cultivated by Mr. Jaune de St.

Hilaire. Mr. Turpin examined it with the microscope to ascertain its coloring matter; various chemists furnished the method of extracting it; the indigo produced from it has been submitted to practical dyers; the Chinese works on the subject have been searched into by Mr. Stanislaus Julien, to see how the indigo was extracted in that country. No question ever occupied more savants in different branches. These researches furnish the following results: A French arpent of 32400 square feet, containing twenty thousand stalks of polygonum, produced four to five thousand pounds of leaves, giving eighty to one hundred pounds of indigo, at seven francs a pound, or six hundred to seven hundred francs the arpent. This is the lowest estimate. The process of extracting the indigo is not yet brought to perfection; notwithstanding which, the indigo obtained gives to cotton a blue color superior to that produced by Bengal indigo.

Should it be thought, that in inquiring into the progress of science, we have confined our views too much to the proceedings of the French Academy at Paris, we would beg leave to remind our readers of the influence exercised by the savants of that learned body over the whole scientific world. It cannot be unknown to any, that it is both the focus toward which all the rays of science converge, and also the centre from which they again emanate. Wherever a discovery may originate, it there immediately becomes a subject of discussion, and helps to supply that inexhaustible source with the light it is constantly scattering around. In the weekly publications of the academy, the substance of the proceedings of the learned societies of all Europe is embodied, and from them all important discoveries, and new scientific facts, are most readily and directly gathered. We regret that our own country furnishes so little to increase the stock, and we hope that this being distinctly seen, will furnish a new argument in favor of the proposed American scientific association, of which we have given an account in another part of the present number of our journal.

LITERATURE. We have already extended this department of our journal so far beyond its due limits, that we can say but little in the present number of the two remaining subjects, that it is intended to embrace; and with respect to literature, the restriction is not to be regretted, as the period has not been one in which it has greatly flourished. Within a few years, many of the most brilliant lights which ever appeared in the intellectual heavens, have sunk below the horizon, and the few others that remain of the same magnitude, are too near its western verge to emit any very strong luminous beams. Who that now lives can hope to see again such a splendid firmament of genius as hung over our heads during the first thirty years of the present century, or who can hope to see the thoughts of men called back from the minor cares and the frivolous pursuits, which now occupy them, to the grand,

and the lofty, and the beautiful, that they were wont to contemplate. The contrast between the immediate past and the years that have gone before, is any thing but gratifying to the lover of letters; the whole intellectual force seems to be expended upon ephemeral productions, penny magazines, and knowledge for the people mind appears to have lost its power of deep thought, and imagination its wings for lofty flight. In the catalogues of the publications in France and Germany for the year 1838, the former amounting to six thousand six hundred and three, and the latter apparently to as large a number, we scarcely find an original work of literature that can be considered as a valuable addition to the stock, and we know not that the English press, during the same period, has produced any thing deserving of more honorable notice. We take great pride and pleasure in turning from the discouraging contemplation of the state of literature abroad, to its improving condition at home for so it certainly deserves to be presented. However little we may have contributed to the advancement of science, for that of literature we have of late years done our full share; and in support of the assertion, we refer to the productions of our press: a few years since, they consisted almost exclusively in reprints of foreign works, and now they are more than half our own; and we may add, that a few years since, scarcely an American book was reprinted in England, and now they form no inconsiderable portion of their new publications. The highest prize in letters of the last year, has been unanimously awarded to an American scholar, and the work which gained it, is everywhere considered as entitled to a place among the most finished and elegant and erudite histories in our language. There are few happier associations in literary history, than those connected with this work, and with that of another of the like character and eminence; associations which unite the names of the daring discoverer of our country, and of the sovereigns by whose patronage he was enabled to undertake the enterprise, with those of two of our most beautiful writers; so that the new world which Columbus gave to Castile and Leon, has in turn given back new glory to him and his patrons Ferdinand and Isabella.

EDUCATION. This subject is daily becoming more interesting in almost every part of our country, and the greatest efforts are made for its advancement, both by legislation and by individual action. Common school journals and school libraries and institutions for forming teachers, are the principal instruments by which the great cause of popular education is advanced, and to all of them we wish all possible success; we would be glad, however, to record some more spirited and efficient exertions for the promotion of higher education, for we are persuaded that knowledge is a power which acts from the summit to the base, and not from the base to the summit. Every body knows the extent and universality of elementary

instruction in Prussia, and therefore we omit many curious details on the subject we had prepared from an admirable summary contained in the Berlin Staats-Zeitung, of November last, and introduce only a few particulars relative to the state of the universities, to show that popular education there does not absorb the whole interest of the nation or government. In the kingdom there are six Universities, at which the students and professors, including lecturers, are as follows:

Giving four hundred and seventy-seven professors, and five thou-. sand and ninety-five students, in a population of fourteen millions, ninety-eight thousand, one hundred and twenty-five. The higher schools, called Gymnasia, preparatory to the University, are one hundred and thirteen in number, with twenty-three thousand three hundred and seventy-one pupils; and the proportion of children at school in the kingdom is between a sixth and a seventh of the whole population.

This proportion is far higher, than that of any other state in Europe. În France it is about one sixteenth; in England the external varies, some accounts making it one eleventh, others only one sixteenth; in Ireland, it is but one fifty-fourth. The returns in our country are not sufficiently accurate to enable us to fix the proportion for the whole union; in the New England states, New York, and some others, careful and detailed reports are made annually, but they do not show as large a proportion of children at school as the Prussian tables; there, however, attendance is compulsory, and the most ample provision made for universal instruction. We cannot compare the proportion of young men at the universities abroad and at home, for we have no institutions corresponding to the universities of Europe; there are seven thousand three hundred and eightyseven in all our colleges the present year; to these should be added the number studying professions under private direction, which we have no means of ascertaining. In fact, the whole state of things connected with education, is so different among us, from its condition on the other side of the Atlantic, that no fair comparison can be presented by means of numerical tables. There are ten thousand students now at the university of Paris, but the whole system of public instruction in France, under its new organization, must be explained before it can be understood, and that does not belong to our present purpose.

QUARTERLY LIST OF NEW PUBLICATIONS.

(Reprints of Foreign Books are marked with an asterisk.)

[Whenever a book is received at the office of the Review, it is entered in the quarterly list, with its full title, and the name of the publisher, and the place of the publication, are added — if not, the short title only is given, without the name of the publisher.]

AGRICULTURE.

The Economy of the Hog Pen; or the raising and fattening of Swine. By Henry Colman, (in press.)

The Silk Grower's Manual. By J. H. Cobb, new edition, 12mo.

BIOGRAPHY AND MEMOIRS.

Library of American Biography, vol. X. By Jared Sparks. Boston: 1838. Hilliard, Gray, & Co. 12mo. pp. 386.

Life of the Cardinal de Cheverus, Archbishop of Bordeaux. Translated from the French of Rev. J. H. Doubourg. By Robert M. Walsh. Philadelphia: Hooker & Claxton. 12mo. pp. 280.

The same.

Translated by E. Stewart. Boston: 1839. James Munroe & Co.

12mo. pp. 389.
Life of Rev. S. H. Stearns.

Private Journal of Aaron Burr. By Matthew L. Davis. 2 vols. 8vo.

Life of George Washington; abridged for Schools. By John Marshall, 12mo. Memoirs of Charles Mathews, Comedian. By Mrs. Mathews. Philadelphia: 1839. Lea & Blanchard. 2 vols. 12mo.

Life of Cowper. By Robert Southey. 2 vols. 12mo.

The Life of George Washington. By Jared Sparks. Boston: 1839. F. Andrews. 8vo. pp. 562.

Biography of Revolutionary Heroes. By Mrs. Williams. 12mo.

EDUCATION.

1. Journals and General Treatises :

The Common School Journal; semi-monthly. Boston: 8vo.
Connecticut Common School Journal; monthly. Hartford: 4to.
Common School Assistant; monthly. New-York: 4to.

Ohio Common School Advocate.

Michigan Journal of Education.

American Annals of Education.

Mutual Duties of Parents and Teachers; a Lecture. By D. P. Page. 8vo. Lectures before the American Institute of Instruction, at Lowell. 1838, 8vo.

2. School Books:

The Eton Latin Grammar; arranged and edited by Rev. James Coghlan. New-York: 1839. Louis Sherman. 12mo.

Publii Terentii Afri. Andrea Adelphique. Ex Edit. Westoviana Accedunt Notæ Anglica. Cura C. K. Dillaway, 18mo.

HISTORY, POLITICS, AND POLITICAL ECONOMY.

History of Ferdinand and Isabella. By W. H. Prescott. 3 vols. 8vo., fifth edition.