One of the most attractive objects to those who visited Edinburgh during the recent sitting of the two Assemblies, was Mr D. O. Hill's great historical picture of "The First General Assembly of the Free Church of Scotland." That picture is now considerably advanced, but will not be completed for two years at least to come. During our late temporary sojourn in the Modern Athens, we availed ourselves of the opportunity of repeatedly visiting the artist's studio on the Calton Hill, and were favoured by him with ample explanations of his views and designs as to the execution and filling up of the picture. Our readers, who have not had the same opportunities, will not be displeased, we are sure, if we give them some account of this great national work.

Mr Hill has been most felicitous in the choice of a subject for the exercise of his genius and his pencil. Every one to whom he first mentioned his idea was struck by it, and enthusiastically cheered him on to the task which he contemplated. On the Saturday after the disruption, happening to meet with one of the most talented of the Judges of the Court of Session, Mr Hill informed him of the work he was meditating. His Lordship was delighted at the thought of it, recommended him to throw his whole heart into it, and not to ruin it for want of time -- adding, that "there had not been such a subject for a great picture since the days of Knox, and not then." The disruption of the Church of Scotland is, indeed, in many respects, a unique event in the modern history of Christendom. Never before, since the age of miracles, was such a multitude of men, who might have availed themselves of so many plausible pretexts for hesitation and delay, seen to advance with so unwavering and unfaltering step, with one heart and one soul, and with a calm and dignified simplicity, to lay on the altar of God their whole emoluments, to the amount of £100,000 a year, as a testimony to the supremacy of conscience, and to the vital importance of the crown rights of the Redeemer. It is this peculiarity in the origin of the Free Church that has invested it with such an absorbing and world-wide interest -- that has excited the most exalted feelings in every generous heart in the most distant lands wherever it has been heard of -- that has startled Atheism in its den -- that has given fresh vigour to Evangelism, through the whole bounds of the one Church of Christ, and has called forth the most rapturous response from Christians on the banks of the Ganges, in the wilds of Australia, and in the dense forests and populous cities beyond the far Atlantic.

Such is the subject which Mr Hill has chosen as the theme of his historical picture, and a more noble one it is impossible to imagine. To secure success in the execution of his design, there is need of a rare combination of qualities, and Mr Hill possesses the requisite qualities in no common degree. He is an enthusiast in the cause of the Free Church, and not only a man of genius and highly cultivated taste, who has already gained for himself a wide and honourable fame as an artist, but one who can fully appreciate those lofty qualities that gave rise to the disruption.

That which will give a peculiar interest to Mr Hill's undertaking, is the number of portraits which it is intended to embrace, and the striking fidelity with which he possesses the means of taking these portraits. The picture will contain between 300 and 500 portraits of the leading and more prominent ministers, elders, and members of the Free Church, and also of various other communions that have sympathised with it.

The interest derived from the individual portraits will be much heightened by the way in which Mr Hill proposes to group them. Although all the figures will probably be portraits, yet there is to be such a selection as shall make them illustrative of various parties and circumstances connected with the great movement -- as shall make the various groups, in short, tell the story of the disruption, with its causes and consequences. Our readers may perhaps like to know something of the arrangement which it is intended to observe in the composition of the picture. Dr Chalmers, of course, is in the chair. Close beside him on the raised platform sit his brother and two sons in law, along with the Rev. Andrew Melville of Logie, who ordained him. A little to the left of the chair are the platform champions, Candlish, Cunningham, Begg, Guthrie, Makgill Crichton, and Andrew Gray. On the Moderator's rigt are Dr Welsh, Sir David Brewster, Professor Fleming, Dr Forbes, Dr Abercromby, Rev. J. Bruce, Sheriffs Speirs and Monteith. Still farther to the right appear Dr Buchanan, and a group of the more prominent clergy and laity of Glasgow and the west. The seats behind are occupied by those Presbyteries which got into conflict with the civil courts, namely, Auchterarder, Dunkeld, Irvine, and Strathbogie, and by other ministers and elders of distinction, arranged according to Presbyteries, or by some other connecting circumstances. In front of the platform stands the Clerk's table, with Dr McFarlane of Greenock in the act of signing the Deed of Demission, and several other ministers coming forward to sign among whom are Dr Brown of Glasgow, the venerable Mr McGillivray of Lairg, and Dr Sommerville of Drummelzier, who appears bending under the infirmities of age, and requiring the assistance of some of the neighbouring ministers to enable him to reach the table. On the right and left of the table are the Procurator of the Free Church, Mr Dunlop, the Clerks, Dr Clason and Mr Pitcairn, the witnesses to the deed, the Treasurers, and other officials. Behind it sit Dr Macdonald of Urquhart, and a group of the Highland clergy; and a little to the left, Mr Burns of Kilsyth, with a group of those ministers who have been most honoured in the work of Revivals. The side seats on the right of the table are occupied by representatives of the different bodies of Dissenters, and by the English and Irish Presbyterian Deputations; those on the left by the representatives of the different schemes of the Church, and the clergy from foreign churches. Connected with the Jewish scheme are Dr Keith, Dr Duncan, Mr Schwartz, &c.; with the India mission, Dr Wilson, Dunjibboy, and Mr S. Hislop; with the School scheme, Mr Macdonald of Blairgowrie, and Mr Lewis of Leith; with the Building scheme, the Architect, with plans, &c. The group of foreign clergymen includes the Rev. A. Sidow of Potsdam, the King of Prussia's chaplain, the Rev. Mr Heintz of Berlin, the Rev. Jacob Abbott, and Rev. J. B. Condit of America, M. Monod of Paris, and Dr Malan of Geneva. On the platform at the right of that appropriated to the more distinguished members appear the ministers' wives and their families; and a similar platform on the left is filled with a group of the more aristocratic laity adhering to the Free Church, including Lord and Lady Breadalbane, Mr Fox Maule, Monzie, and many others.

Such is a sketch of the proposed grouping of the picture. By adopting something of this plan, Mr Hill will be enabled to add to the interest derived from mere portraiture, the still more important qualities which go to constitute the ingredients of a most deeply interesting historical work -- a work which will afford an opportunity of highly picturesque arrangement, of grand variety in exhibiting the national character, as it appears in both sexes, and all ages, ranks, and costumes -- a work in which will be vividly represented a deed of devoted heroism, such as the world has seldom witnessed, calling up in the minds, and consequently in the looks, of the actors and speculators, the most exalted expression of devotion, admiration, and sympathy, and those strangely mingled feelings of godly sorrow and holy joy, which were exhibited on that memorable day when our spiritual Bannockburn was achieved.