A WORD ON INK. [From Chambers's Edinburgh Journal.]

New Zealand Spectator and Cook's Strait Guardian, Volume VI, Issue 472, 9 February 1850, Page 4

A WORD ON INK. [From Chambers' s Edinburgh Journal.]

The ancients knew better how to make ink of a durable colour than we do. Modern inks are metallic preparations, and on this account they are liable to deterioration by atmospheric action. The cause of the superiority of inks of old date has been earnestly and satisfactorily investigated by Professor Traill. It appears that up to the fourteenth century, the inks employed for the purposes of writing on manuscripts were almost without exception, fluids in which the deep colouring material was not metallic, but carbonaceous matter. From that time to the present, however, a preparation much resembling our present fluid was employed, to the inexpressible regret of antiquarian manuscript lovers, and possibly to the serious loss of many historical facts of value. From this period, therefore, as a general rule, commences that race of yellowish, reddish, or greenish-coloured manuscripts, which no patience can decipher, nor any means satisfactorily restore to life. Although it appears probable that occasionally, metallic ingredients were added to the ancient ink, yet there can now exist no doubt that the persistence of colour by which they are distinguished was entirely due to the carbonaceous matter employed in their composition. \ A curious passage in Pliny seems to have led Professor Traill to a discovery which, in spite of its apparent insignificance, we justly consider, to ba among the most important in appliedfsheraistry — a good fluent, black, in-

delible, unchangeable ink ! Pliny recommends, among other receipts for the preparation of ink, an ink made of carbonaceous matter diffused in a solution of animal glue in vinegar. The only difference between Dr. TraiU's ink and this is, that instead of animal glue he uses vegetable gluten. But tbis simple discovery was not arrived at without labour and expense ; and to form an adequate conception of the thorough investigation Professor Traill instituted on the whole subject, it is only necessary to refer to his paper, printed in the 14lh volume of the 'Transactions of the Royal Society of Edinburgh.' In the true and generous spirit of the best philosophy, he has there detailed, without reserve, the process by which he prepares this valuable fluid ; and desirous as we are to effect a revolution in the kingdom of metallic ink, and to put a worthier ruler of its important affairs at its head, we cannot do better than transfer the process from those to these pages. The first step is the preparation of the gluten. If a small mass of dough is kneaded underneath a little stream of water for some time, it will be found that it has parted with all the starch it contained, and that only a tough, sticky mass is left in the hand. The more carefully this is done, the purer will the remaining gluten be. Now, to ten parts of the liquid sold by chemists under the name of pyroligneous acid, which is an impure acetic acid, one and a-half parts of gluten are to be added, and the whole left under a covered vessel, and submitted to a gentle heat. In about twenty-four hours a solution of the gluten is effected, and a saponaceous fluid remains. To form this into an ink, the very finest lamp black must be- procured, and used in the proportion of from eight to twelve grains to each ounce of the liquid, rubbing it quite smooth with the pestle and mortar. When this operation is completed, the fluid is quite ready for use, and will be found completely to fulfil all those postulates which the constitution of a good and permanent writing fluid demands. The addition of a little bruised allspice, cloves, or cinnamon, gives the liquid an agreeable aroma. This ink has been submitted to the most severe tests. In a solution of chlorine gas strong enough to bleach in a few minutes the blackest writing ink, a slip of paper written with new ink lemained fventy-four hours j without the least change, and was subsequently exposed for seventy-two hours to its influence with the same result. Exposed to the sun and air, it only became of a more intense black hue, and was more fixed in the paper. It was not in the least affected by water, strong alkalies, or acids, not even the pyroligneous acid. Like every other ink, it may be washed off parchment, the surface of that substance refusing its admission to the texture of the material ; but for every other purpose it is incomparably superior to every ink now in use. Professor Traill modestly writes : — ' It is only offered as a writing-ink well suited for the drawing out of bills, deeds, or wills, or wherever it is important to prevent alterations in sums of money, or of signatures, as well as for handing down to posterity records in less perishable materials than common ink.' It is perhaps one of the best testimonials to its value, that it is exclusively employed now in several large commercial houses and banks, and in the National Bank of Scotland. Setting aside the value of this discovery, as affording a faithful and imperishable recording fluid, we would urge its extensive adoption as a preventive of fraud. No one who knows human nature will doubt the expediency of hedging up, so far as is practicable, the narrow road of rectitude ; by this means, we believe, not only would an additional security be given to the honest, but an additional, and apparently insurmountable, difficulty would be put before the path of those who are unhappily otherwise inclined.