We will now briefly enumerate some of the advantages which the Colonies and Dependencies enjoy from their connection with Great Britain. Few words need to be expended on this part of the question, as by those who advocate their dismissal it is admitted that the colonists enjoy a balance of advantage greatly in their favour. It certainly must be a benefit of no ordinary kind, that in their infant and nascent state the colonies should be spared the expense of their own defence, and be secured by the power of the mother country from every external interruption in the development of their energies. Here, also, may they find capital for their enterprizes at rates of interest lower than on any other exchange in the world. Here is a market whose gates are never shut for their every production; factories thirsting for the raw produce which their new tilled lands can give, and where they may purchase at the lowest possible price every manufactured article they can possibly require. The new settlers carry with them a literature the growth of ages, and enriched with the marvellous fruits of a genius as noble as any the world has ever seen. The political experience of generations is theirs, by which to mould the new governments they establish; and principles already confirmed by practice, are prepared for their guidance. Laws justified by age are already framed by which to limit or determine the rights of every class, or afford rules by which justice may decide all matters referred to her arbitrement. Not less influential or advantageous are those moral and religious sentiments which breathe through all ranks in the mother country and dominate all opinion at home, and which, borne to new fields, to new climes, or among other peoples, may bear still nobler fruits of excellence and virtue in the ages to come, or regenerate an effete civilization, or give to nations debased by idolatry a new and a loftier intellectual and spiritual life.

Our Colonies open a new career for our youth, an honourable field for the display of abilities which in the crowded streets of the mother country might never find a fitting opportunity. Civilization is borne to fields where new conquests may be made, and the arts and sciences win new laurels. England may rejoice to see her constitution reproduced in new and more perfect combinations, her free legislature transplanted to other climes, and her ideas of responsible government, her impartial tribunals, her personal liberty, her free thought, and above all her religion, root themselves in wider regions and spread out into mightier realms and empires. These rising kingdoms may well desire to retain a connection so precious in all its features, and, by wise arrangements, continue for many years to enjoy all the advantages that the settled government of England can afford and its power secure, until matured by political experience, strong in numbers and wealth to defend the liberties their parent has fostered and their own experience has improved,

they may be free from longer tutelage. Arrived at their political majority they may pursue a career of honourable endeavour, equalling or even transcending in nobleness and blessed results that of the nation which gave them birth.

But it is asked why may not all these advantages be enjoyed, and yet the mother country be free from the cost of securing them? Why should the English at home be taxed for colonies which are rising in wealth, and employing their security and their light burdens for their own sole advantage? In reply to the latter question it has been shown that the Colonies, as a whole, more than repay their cost; and that answer might suffice. But the example of the American protective tariff, followed in some measure by Canada, proves, that when independent these colonies may adopt principles of commercial legislation directly antagonistic to the interests of the mother country. While the connection subsists, and the home government retains the power of disallowing colonial ordinances, there will remain the opportunity of preserving an uniform code of commercial law, and a restraint be placed on selfish and narrowminded legislation. Already this tendency has become apparent in the Colonies where local legislatures exist. No independent nation has yet followed the free-trade legislation of Great Britain, and indications are not few that our Colonies would revert to the system of protection were they freed from the ties that bind them to the mother country. Because our trade with the United States has grown to large dimensions since their independence, it does not follow that other colonies would in similar manner expand their trade with England. But for its inimical tariff, there can be no doubt that our American trade would have expanded to more gigantic proportions; and it is because we cannot secure ourselves against hostile tariffs on the part of independent nations, that it continues to be necessary to our trade and manufactures that we should retain some hold on our Colonies, where an open market may be preserved.

Less appreciable, perhaps, but certainly not less important to our Colonies, are those moral, intellectual, and religious influences which the connection enables Great Britain to exercise, and which would be largely diminished by separation.

An independent people is naturally jealous of interference. The United States have shown us enough of this, and our Colonies too, where we have seemed to them to overstep the bounds of moderation. But the free interchange of thought and pursuit which now goes on between the mother country and her colonial children, contributes greatly to their growth, and which, to a certainty, would undergo diminution in case of severance of interests, even if it did not degenerate into actual antagonism.

We do not enter here on the question of the disadvantages

which may rise out of a state of war, both to Great Britain and her dependencies. War is, or ought to be, an abnormal state of things, and its effects will be as varied as is the position of the colonies, and the nation with whom war is being carried on. Our Colonies would need protection, and be a cause of weakness to us, only in the case of war with a great maritime power. In a continental war they would add to our strength.

We seem then to have been brought to the conclusion, that the advantages enjoyed by the Colonies of Great Britain and the mother country from their connection are many, and that under present circumstances, the lifting the colonies into independent nations would be productive of injury to both.

A MESSAGE FROM THE SUN.

IF during bright daylight you darken a room by closing the shutters, and then bore a small hole through one of those shutters, you will observe on the opposite wall a patch of white light. This patch will vary in size according to the size of the hole and its distance from the wall. But it will always be round (if the hole be round), and will always consist of white light, and will therefore only appear coloured according as the paper covering the wall is coloured.

If, now, you take a prism, or triangular piece of glass (such as hang down from chandeliers, or are often used as knife rests at table), and place one side of it over the hole, close to the shutter, either on the outside or inside, it does not matter which, you will find that the patch of light has become oblong instead of round; and instead of being white, is now made up of seven bands of seven different colours, placed in a fixed order one after the other, red, orange, yellow, green, blue, indigo, and violet, all distinct, and yet toned down so as to mingle well one with the other. This patch is what philosophers call a spectrum. You can always make it appear by following the above directions. It is altogether caused by the shape of the prism. Nothing but a prism will do. But it 1s not necessary that the prism should be made of glass. Other transparent bodies will do, some as well, others better, others not So well.

The spectrum I have described, being obtained from sunlight, is called a solar spectrum. But you may get the same oblong

spectrum, with the same coloured bands, from any of our usual artificial lights. If, for instance, you allow a bright gas-light, after passing through a small hole and a prism, to fall upon a white screen in a dark chamber, you will get a spectrum apparently exactly like the solar spectrum; and the same with an oil-lamp, and the drummond, or the electric light. With all these you will get what are called artificial spectra, apparently exactly like the solar spectrum.

I say apparently, because in reality there is a very great difference, which, however, can only be detected by very careful examination. If your hole be very small, and especially if instead of being round, it be a mere slit with very thin edges, and if you let the light fall, not on a wall, but on the front of a telescope of moderate power, and having placed your eye at the other end, carefully adjust the focus of the instrument, you will find that in the solar spectrum there are a very great many dark bands or lines passing across it, but in the artificial spectra you will find no such lines. If you take an ordinary plain white ivory paper-knife, and colour it with bands of various colours, beginning with red at the bottom of the handle and ending with violet at the point, that will give you a very fair idea of the spectrum, as seen when the light is sent through a slit. If now, with lead pencils of various blackness, you draw ever so many parallel lines across your spectrum from side to side, making some broad, others fine, some dark, others light, crowding them together in some parts, letting them be wide apart in others, you will have a good representation of the dark lines which are seen in the solar, but in no artificial spectrum.

These dark lines are called Frauenhofer's lines, because it was he who discovered them. They are perfectly constant, always to be found in sun-light, are not in any way caused by the nature or quality of the prism, have each their fixed place in the spectrum so that they can be named and recognised, and their distances from each other, or from the ends of the spectrum, or from any particular point of it, accurately measured. For instance, there is one par ticular line in the yellow space, which they call D, and another in the red called A, and between the two, there are a fixed number of other lines at fixed distances, each of a fixed breadth and darkness. Wherever there is sunlight, there, if you look for them, you may find these lines. They are the letters, the hieroglyphics of the sun's message to the earth, and for a long while men wondered what their meaning could possibly be.

But within the last few years our philosophers have learnt to spell out something of these strange symbols, and the way they managed it was as follows: The spectra of our artificial lights have, as I said, no dark lines, and are therefore called continuous ;

for the lines being merely spaces where light is altogether absent, when they are away the light reaches without break from one end of the spectrum to the other.

Our artificial lights are prized for giving a comparatively white ught, and the whiter the light the more they are valued. But there are many substances which, when burned, give a light having a very marked colour. Thus the metal sodium (as, for example, it occurs ints compound chloride of sodium, which we generally call table salt gives a yellow light; the metal barium a green; copper also a green; strontium a red; potassium a violet; and so on. These facts are well known to firework makers, and are often of use to chemists in ascertaining the presence or absence of any particular body.

If now a white light gives a continuous spectrum with all the colours from red to violet, what sort of spectrum can we expect to have from a yellow or red light, or from a light having any particularly definite colour? The answer is that only that part of the spectrum is visible which corresponds to the colour of the light. Thus with a yellow light, we see only the yellow part of the spectrum, all the rest being invisible; with a red light, we only see the red, and so on, the yellow being in exactly the same place as the yellow part of the spectrum would be if the whole of it were visible. And the other colours in the same way. If however we examine our results with greater care and delicacy, we shall find a more curious result. Let us take a good prism, a good telescope, and a very faint light, such for instance as a spirit lamp with the cohol so diluted with water that it will only just burn. We shall then get only a very faint spectrum. If now we introduce a little table salt into the flame of the spirit lamp, we shall get a yellow fame, and if we look through the telescope we shall find not a yellow light all over the yellow space of the original spectrum, but only one narrow bright yellow band across one particular part of it. Repeat the experiment as often as you like you will always get the same result. Hence this bright yellow band in one particular part of the yellow space is called the "sodium spectrum.” If you had a substance, of whose nature you were ignorant, and were to burn it in such a flame as I have described, and found gave that bright yellow band in that particular place, that is to say, gave the sodium spectrum when viewed through the spectrocope, (for such is the name given to the arrangement of prism and lescope) you might say without any fear at all of error that the substance contained sodium. If instead of sodium we burn in the flame a small quantity of the metal lithium, we shall find a red band produced in another particular part. And this red band will be the only thing we shall see, the rest of the spectrum being This red band is then the lithium spectrum, and by it we can recognize the presence of lithium.

invisible.