For a time, perhaps through a period of several centuries, a mixture of the two kinds of ink was employed by the Romans; and this was undoubtedly the best composition that was ever invented for the purpose of deliberate, careful, elegant writing, designed and required to be permanent and unchangeable under constant exposure and handling,—as in the case of manuscript books before the art of printing was known. Even as early as the first century of the Christian era, in the time of Pliny the Younger, and probably long before that, a solution of sulphate of iron was commonly or frequently added to the carbonaceous and oleaginous mixture which we have described as the original writing-ink. In short, the _atramentum sutorium_ was added, in moderate quantity, to the _atramentum scriptorium_, thus constituting it a CHEMICAL as well as a MECHANICAL ink. So, modern ink may be improved in blackness, durability and beauty, and rendered unchangeable in color under the action of the chlorides, acids, &c., by the intermixture of a small quantity of the very finest carbon, in the form of an impalpable powder. But, the great difficulty is—that the carbon clogs the pen, and renders the ink too thick to flow easily, so that it can never be used for rapid or ordinary writing. We can not give, in our own words, a better account of this matter than we find in the language of a very learned author in the Edinburgh Review, (volume 48, Dec. 1828). The article here cited is entitled “THE RECOVERY OF LOST WRITINGS,” and is nominally a review of [1]GAII INSTITUTIONUM COMMENTARII: [2]INSTITUTES DE GAIUS, RECEMMENT DECOUVERTES DANS UN PALIMPSESTE DE LA BIBLIOTHEQUE DE CHAPITRE DE VERONE. [3]JURISCONSULTI ANTE-JUSTINIANEI RELIQUIAE INEDITAE, _ex codice rescripto Bibliothecae Vaticanae_, _curante_ ANGELO MAIO, _Bibliothecae ejusdem Praefecti_. The article begins on page 348 of this volume of the Review.