ing the spectrum is likely to lead to very great results, for the records thus obtained are absolutely correct, and far surpass in accuracy the efforts of the inost skilful draughtsman. It must be understood that in all these researches the spectroscope is allied with the telescope, otherwise the small amount of light furnished by some of the bodies under examination would not be enough to yield any practical result.

The clusters of matter which are called nebulæ, and which the most powerful telescopes have resolved into stars, are shewn by the prism to be nothing but patches of luminous gas, possibly the first beginnings of uncreated worlds. Comet-tails are of the same nature, a doubt existing as to whether their nuclei borrow their light from the sun or emit light of themselves. We may close a necessarily brief outline of this part of our subject by stating that it is possible that the spectroscope may some day supplant the barometer, more than one observer having stated that he has discovered by its aid signs of coming rain, when the latter instrument told a flattering tale of continued fine weather. We have merely shewn hitherto how the spectroscope is capable of identifying a metal; but its powers are not limited to this; for by a careful measurement of the length of the absorption lines, a very exact estimate of the quantity present can be arrived at. This method of analysis is so delicate that in experiments carried on at the Royal Mint, a difference of one ten-thousandth part in an alloy has been recognised. Neither must it be supposed that the services of the spectroscope are confined to metals, for nearly all colored matter ean also be subjected to its scrutiny. Even the most minute substances, when examined by the microscope in conjunction with the prism, shew a particular spectrum by which they can always be identified. Nor does the form of the substance present any difficulty in its examination, for a solution will shew the necessary absorption bands. Blood, for instance, can be discovered when in a most diluted form. To the physician the detection of the vital fluid in any of the secretions

is obviously a great help to the diagnosis of an obscure case. But in forensic medicine (where it might be assumed that this test would be of value in the detection of crime) the microscope can identify blood-stains in a more ready manner.

The simple glass prism as used by Newton, although it is the parent of the modern spectroscope, bears very little resemblance to its gifted successor. The complicated and costly instrument now used consists of a train of several prisms, through which the ray of light under examination can be passed by reflection more than once. By these means greater dispersion is gained; that is to say, the resulting spectrum is longer, and consequently far easier of examination. A detailed description of the instrument would be impossible without diagrams, but enough has been said to enable the reader to understand theoretically its construction and application.

It will be understood that we have but lightly touched upon a phase of science which is at present quite in its infancy. It is probable that many more remarkable discoveries will in course of time be due to the prism. Already, within the past twenty years, four new metals have by its aid been separated from the substances with which they were before confounded; and although they have not at present any commercial value, we may feel sure that they have been created for some good purpose not yet revealed to us. There are signs that the spectroscope will some day become a recognised adjunct to our educational appliances.

It is even now included under the head of Chemistry in the examination of candidates for university honors, and there is no doubt that it will gradually have a more extended use. Many years hence, when generations of School-Boards have banished ignorance from the land, the spectroscope may become a common toy in the hands of children, enabling them to lisp :

Twinkle, twinkle, little star; We know exactly what you are.

Chambers's Journal.

THERE is a curious difference between the two parts of the "Low Countries"the "

nether lands" formed of the ooze and mud deposited by the three great rivers, the Rhine, the Meuse, and the Scheldt, before entering the North Sea, and defended by a fringe of sandbanks and "dunes," thrown up by the winds and the waves. Belgium is simply a flat, ugly, prosperous-looking, uninteresting country, not unlike the more commonplace parts of England; but the flatness of Holland has infinitely more character in it, so that after passing the wide and turbid Scheldt, with its forests of shipping, one feels as if in a new land. It is the difference between a merely plain person and an ugly face full of character.

We left Antwerp on a grey day, with occasional gleams of light, the spire of the cathedral seeming for a time to grow taller and taller, as the perspective of distance showed more clearly the true relation of its height to the churches and houses, the masts and chimneys, grouped round its central point-the delicate tracery of its lofty pinnacles, rising 400 feet above the little men who yet had ventured to build up that daring flight of masonry heavenward.

The dead flats, with trees and distant houses, and shifting islands of light on the bright green meadows, passed quickly by,-living illustrations of the Dutch pictures with which we all are familiar; the exquisite truth of which to nature strikes one at every turn, the land part of the scene forming a mere line in the whole subject, the sky and clouds, as at sea, monopolizing three-fourths of the composition, and requiring therefore infinitely more care and thought in their arrangement than with other landscapes. Presently came a series of small pine woods, cut for fuel and the service of the rail before they could reach the age of any beauty; with wide tracts of sandy, heathery common, and sour boggy bits, where turf was being taken out, and waste corners where more scrubby trees were attempting to grow. Few cottages, no châteaux, hardly any inhabitants, were to be seen; it seemed as if we were

reaching the very end of the world. Then came the marshy flats, always at the mercy of a few inches' rise in the tidal rivers, and the intricate series of islands, which alter as the muddy channels of the there great rivers divide and change, the rushing waters eating away the low-lying lands they have themselves formed, and carrying them bodily into the sea, against whose inroads the very existence of Holland is a continual struggle of life and death.

Here, in this apparently remote corner of the earth, name after name was shouted, as the stations succeeded each other at short intervals, recalling some of the most stirring scenes that the world has ever known, and reminding one how in the sixteenth and seventeenth centuries this was the place where many of the greatest deeds in European history were enacted, and the most important negotiations were conducted.

Here was the centre of the great struggle for freedom, both religious and political, won hardly for Europe at the cost of such horrible sufferings to the inhabitants of these industrious, well-doing cities,-ingrained traders if ever any existed,-who yet gave up the prosperity so dear to them for the sake of what to some seem only mere abstract questions; -where women and children helped in fighting the good fight, both actively and passively, not only enduring to the end the dreadful privations of the sieges, and exhorting their mankind not to yield, but even themselves fighting on the ramparts. Here such heads of the people as William the Silent, Barneveldt, De Witt, Prince Maurice, and William III. revolved their great schemes of European policy, and moved the strings that moved the world.

After such a past, it seems strange how the current of political power has now, as it were, stranded Holland on her own mud-banks, and left her to her prosperous trade, the commercial activity which fills the ports of Rotterdam, Dort, and Amsterdam with shipping and goods, the interior development of her agriculture over miles of flat green pastures,

discovered their value at a time when it was lowest among their own countrymen, and perfect gems of art were bought for mere trifles, which would now be recovered, if possible, at almost any price. The city of Antwerp has just given £4,000 for a picture by Hobbima, not two feet square. Why has all this power passed away? why cannot the city cause a new picture to be painted equal to the old?

In literature they stood nearly as high. Erasmus was certainly the leading philosophical thinker of the Reformation. Grotius, the "miracle of Holland," the "rising light of the world," as he was termed; Descartes, though not born among them, yet who certainly must be ranked among their great men; Spinoza, great among the greatest as a thinker," the "God-intoxicated man," as he was called by the Catholic Novalis,-who was anathematized by orthodox Jew and Christian alike, but whose reputation has survived the reprobation; and Boerhaave," the physician of Europe," were a few typical names among them; while printing, whose delicate clearness and beauty has never been excelled, amounting indeed to an art, was carried on by the family of the Elzevirs, at Leyden and elsewhere. In etching, Rembrandt himself has no rival, in power and delicacy alike, and in the effects of color produced, though in mere black and white, by the magic of his light and shade. The etchings, however, which bear his signature are of very various merit, and the backgrounds, foregrounds, and draperies are now believed to have been often worked in by his many pupils. Ferdinand Bol, himself an excellent painter, is also supposed to have filled in sketches made by Rembrandt himself. As far as mere mechanical power goes, Hollar's touch seems to be hardly inferior to that of the great master; but the genius of invention behind it is lacking in his case, and the satins and furs, the ruffs and lace, so marvellously rendered, continue mere “furniture," without the wondrous application by which Rembrandt imparts to them such surpassing interest.

Presently we passed the low earthworks of Breda, which look so weak and insignificant that they would seem impossible to defend; but their "surrender" was deemed such an inportant tri

umph that it was immortalized by Velasquez, in the great picture of the Madrid Gallery, so bristling with uplifted lances, that it is technically called "Las Lanzas." To us a far more interesting incident is the surprise of the town in 1590, while in the possession of the Spaniards, by a devoted band of soldiers, headed by a captain of Prince Maurice's army. Seventy men hid themselves in the hold of a barge, under a load of turf, which was going into the town for the supply of the troops. The voyage was only of a few leagues, but the winter wind blew a gale down the river, bringing with it huge blocks of ice, and scooping the water out of the dangerous shallows, so that the vessel could not get on. From Monday till Saturday these brave men lay packed like herrings in their little vessel, suffering from hunger, thirst, and deadly cold. Only once did they venture on shore to refresh themselves. At length, on Saturday evening, they reached Breda, the last sluice was passed, the last boom shut behind them.

An officer of the guard came on board, talked to the two boatmen, and lounged into the little cabin, where he was only separated by a sliding door from the men; a single cough or sneeze would have betrayed them, when every one of these obscure heroes would have been butchered immediately. As they went up the canal the boat struck on some hidden obstacle and sprung a leak; they were soon sitting up to their knees in water, while pumping hardly kept the barge afloat. A party of Italian soldiers came to their help, and dragged the vessel close up to the guard-house of the castle. The winter had been long and cold, and there was a great dearth of fuel. An eager crowd came on board, and began carrying off the cargo much faster than was safe for the hidden men. The hardships they had endured and the thorough wetting had set the whole party coughing and sneezing; in particular the lieutenant, Held, unable to control his cough, drew his dagger, and implored his neighbor to stab him to the heart, lest the noise should betray them. The skipper and his brother, however, went on working the pumps with as much clatter as possible, shouting directions to each other so as to cover the sounds within. At last, declaring that it was now

dark, they with difficulty got rid of the customers. The servant of the captain of the guard lingered still, complaining of the turf, and saying his master never would be satisfied with it. "Oh," said the cool skipper, "the best part of the cargo is underneath, kept expressly for the captain; he will be sure to get enough to-morrow.'

The governor, deceived by false rumors, had suddenly gone to Gertruydenberg, leaving his nephew in charge-a raw, incompetent lad. Just before midnight the men stole out; one half marched to the arsenal, the other to the guard-house. The captain of the watch sprang out and was struck dead at one blow, while the guard were shot through the doors and windows. The other band were equally successful; the young governor made a rally, but was driven back into a corner of the castle, while the rest of the garrison, belonging to Spinola's famous Sicilian legion, fled helter-skelter into the town, not even destroying the bridge behind them. A body of picked troops and Maurice himself soon arrived, the palisade was beaten down, and they entered by the same way as the fatal turf boat. Before sunrise the city and the fort had surrendered "to the States-General and his Excellency." The capture was not only important in itself, but was the beginning of a series of Dutch victories, the turn in the tide after the Spanish triumphs of previous years.

Next came Dort, with its bright little gardens, houses, churches, ships, canals, windmills, and river,-all seeming inextricably mixed, and a savor of the Synod collected here to settle the Calvinistic, Lutheran, and Arminian disputes of Protestant countries, not very satisfactory in its results, as it settled nothing. The place was a favorite subject with Cuyp, and the numerous "Views," two of which were to be seen in the last Loan Collection, the Landing of Prince Maurice at Dort" in the Bridgewater Gallery, with Mr. Holford's "View of Dort," are at least a much more beautiful consequence due to the existence of the town.

There is a curious romance about this picture; it was very long and narrow, and was cut in two by an unscrupulous

dealer, thus utterly ruining the composition and balance of color, particularly in the sky. The two halves remained apart for years and were called "Morning" and "Evening," in the strange ignorance of both buyers and sellers of what constituted early light. At length the true relation of the parts was discovered, they have been once again married, and shine in the full glow of their warm beauty on Mr. Holford's walls: one can hardly help feeling that they rejoice in their reunion. The luminous effect of the evening light on sky and river, hot and still, with the town and its windmills, and the summer morning effect of the "Landing," are equally admirable. The atmospheric effects in Holland are certainly very peculiar. When the landscape is not blotted out by the mists, the fog, and the rain, its extreme flatness (as at sea) allows long perspectives of light to be seen under the clouds down to the very low level of the horizon. This often produces wonderful beauty of light and shade, when the sun is shining on any point in the great sweeps of country generally there in sight. The chances of variety are also much greater with such an immense arch of sky, than when the lower circle is cut off all round by trees and undulations, more or less high, as is usually the case elsewhere. There is also a singular clearness in the air over great expanses of water or watery land, and of vivid color when the cloud-screens lift, which is infinitely attractive; while the reflected light from the plains of bright water gives a remarkable luminousness-which has certainly passed on to the canvas of the Dutch artists.

Further down the Maas comes Rotterdam, which is now the entrepôt for the trade between Java and Germany. It looks busy and full of life, with its forests of masts on the broad, muddy, rapid river, washing away a bit of land on one side, piling it up further on, on the everchanging morasses formed where the Maas reaches the sea. Here first one sees that strange combination of dark red brick houses, trees, and canals, most picturesque, and strikingly unlike anything else in the world. Even Venice, to which it is so often compared, resembles it in the words of a description far more than in reality. The Dutch towns,