The common of Dalkey is now a place of life--a suburb, as we might say, of the city; but at the period to which we have alluded, it was ordinarily a scene of the most desert solitude. A few cottages stretching from the village along its southern boundary, and a solitary cabin originally built by miners, and which still remains, were the only habitations to be seen. But though thus uninhabited, it was not at all times a scene of loneliness. On Sundays and other holidays its rocks and dells were peopled with numerous pic-nic or sod parties of the middle class of the citizens. The song went round, and the echoes were startled by the merry notes of the fiddle or the flute, to which the several groups of happy dancers footed the Irish jig and country dance. Nor were such pic-nics confined exclusively to the citizens of the middle class--the sporters of jaunting cars and jingles. Parties of the higher ranks occasionally assembled here on week days, and had their rural fetes on a larger and more magnificent scale. It was our own good fortune to be an invited guest to one of these, of which we may be permitted to give some account, as an example of a state of manners and usages of society in Ireland now no longer to be found in persons of the class to which we refer. It was a pic-nic party given by the Alexanders, the Armits, and the present popular and deservedly honoured veteran the Commander of the Forces in Ireland--then lieutenant-colonel of the 18th or Royal Irish Fusileers, which were at the time quartered in Dublin. On the morning of as beautiful a day in June as ever came, the inhabitants of the leading thoroughfares of the city, and those along the road side from Dublin to Dunleary, were surprised by the unusual crowds of open carriages of all kinds conveying the youth and beauty of the aristocracy of the metropolis to the chosen scene; and when the fine band of the Fusileers, in their magnificent full-dress uniforms of blue and gold, were seen to pass along on the same route, innumerable parties of the inferior ranks of the inhabitants of the city and south-eastern suburbs were hastily formed to follow in their wake. At noon, or a little after, not only the majority of the original party were assembled in a beautiful and extensive green amphitheatre, surrounded by rocky cliffs, but those cliffs were themselves covered by a crowd of smaller parties--tributary stars around the more splendid galaxy that occupied the centre of the brilliant scene.