The worth of the diary must depend on the diarist; but “Of the things which concern himself,” as MARCUS ANTONINUS entitles his celebrated work —­this volume, reserved for solitary contemplation, should be considered as a future relic of ourselves.  The late Sir SAMUEL ROMILLY commenced, even in the most occupied period of his life, a diary of his last twelve years; which he declares in his will, “I bequeath to my children, as it may be serviceable to them.”  Perhaps in this Romilly bore in mind the example of another eminent lawyer, the celebrated WHITELOCKE, who had drawn up a great work, entitled “Remembrances of the Labours of Whitelocke, in the Annals of his Life, for the Instruction of his Children.”  That neither of these family books has appeared, is our common loss.  Such legacies from such men ought to become the inheritance of their countrymen.

To register the transactions of the day, with observations on what, and on whom, he had seen, was the advice of Lord KAIMES to the late Mr. CURWEN; and for years his head never reached its pillow without performing a task which habit had made easy.  “Our best and surest road to knowledge,” said Lord Kaimes, “is by profiting from the labours of others, and making their experience our own.”  In this manner Curwen tells us he acquired by habit the art of thinking; and he is an able testimony of the practicability and success of the plan, for he candidly tells us, “Though many would sicken at the idea of imposing such a task upon themselves, yet the attempt, persevered in for a short time, would soon become a custom more irksome to omit than it was difficult to commence.”

Could we look into the libraries of authors, the studios of artists, and the laboratories of chemists, and view what they have only sketched, or what lie scattered in fragments, and could we trace their first and last thoughts, we might discover that we have lost more than we possess.  There we might view foundations without superstructures, once the monuments of their hopes!  A living architect recently exhibited to the public an extraordinary picture of his mind, in his “Architectural Visions of Early Fancy in the Gay Morning of Youth,” and which now were “dreams in the evening of life.”  In this picture he had thrown together all the architectural designs his imagination had conceived, but which remained unexecuted.  The feeling is true, however whimsical such unaccomplished fancies might appear when thrown together into one picture.  In literary history such instances have occurred but too frequently:  the imagination of youth, measuring neither time nor ability, creates what neither time nor ability can execute.  ADAM SMITH, in the preface to the first edition of his “Theory of Sentiments,” announced a large work on law and government; and in a late edition he still repeated the promise, observing that “Thirty years ago I entertained no doubt of being able to execute everything which it announced.”  The “Wealth of Nations” was but a fragment of this greater work.  Surely men of genius, of all others, may mourn over the length of art and the brevity of life!