ON THE MANUFACTURE OF WRITING INKS.
In the manufacture of good writing ink, more nicety is required in the choice of materials, as well as greater skill in manipulation, than is generally bestowed upon it.
The proportion of the various ingredients used is a matter of considerable importance, affecting in a great degree the durability of the ink.
DR. LEWIS’S WRITING INK.—Dr. Lewis, who instituted a series of very careful experiments on the manufacture of writing ink, found that equal parts of sulphate of iron and of galls gave an ink, which, although of a good color when first used, became yellowish-brown when the writing was kept for a moderate length of time, and that in proportion to the quantity of the sulphate, the inks were less durable in color, and that those in which the galls were in excess, were most durable.
He, therefore, recommended the following proportions as best suited for the manufacture of good writing ink:—Powdered sulphate of iron, 1 oz.; powdered logwood, 1 oz.; powdered galls, 3 oz.; gum arabic, 1 oz.; white wine or vinegar, 1 quart.
Water will answer for common purposes, but white wine formed a blacker ink than water, and vinegar formed one still blacker than wine. The addition of spirit injured the color, and occasioned a precipitation of coloring matter—a decoction of logwood, instead of water, improved both the beauty and deepness of the black. The ingredients are to be put in a glass or other convenient vessel, not metallic, and the mixture shaken four or five times a day. In ten or twelve days it will be fit for use, and sooner if in a warm situation; but it continues for a long time to improve if left without decantation. When it is separated from the powdery residue, it will be kept in a good state with greater certainty, if some broken galls freed from the powder and some pieces of iron are put into it. Iron, however, is the only metal which it is safe to retain in contact with the ink.
Dr. Lewis gave the preference to distilled or rain water in {306} the manufacture of ink, but it seems probable that a water containing a certain proportion of carbonate of lime is more suitable. In dyeing a black color by means of galls or sumach and copperas, hard spring water is preferred by some dyers. To produce in a liquid a given depth of color, distilled water requires more dyestuff than common spring water. This is illustrated in the following experiment, devised by Mr. Phillips: into two glass jars of the same size, each half-filled with distilled water, introduce equal quantities of infusion or tincture of galls or sumach, and an equal number of drops (only three or four) of a solution of copperas; a faint purplish color will be developed in both jars, but if one is filled with spring water, the color in that rapidly becomes dark reddish-black, and one-half more water is required to reduce it to the same shade of color as the other. The water which is found by experience to be best adapted for dyeing with galls and sulphate of iron, differs from distilled water in containing sulphate of lime, carbonate of lime held in solution by free carbonic acid, and chloride of calcium. The beneficial ingredient seems to be the carbonate of lime, which possesses slight alkaline properties, for if the smallest quantity of ammonia or of bicarbonate of potash is added to the distilled water in the above experiments, the purple color is struck as rapidly and as deeply as in the spring water; chloride of calcium and sulphate of lime, on the contrary, produce no sensible change either in the depth of color or the tint. The effect is no doubt referable to the action of the alkali or lime on the proto-sulphate of iron, by which the sulphuric acid of the latter is withdrawn, and hydrated protoxide of iron set free, for protoxide of iron is much more easily peroxidized and acted upon by tannic and gallic acids (the dyeing principles of galls) when in the free and hydrated state, than when in combination with sulphuric acid. Neither the caustic fixed alkalies (potash and soda) nor their carbonates can be well introduced in the above experiments, as the slightest excess reacts on the purple color, converting it into a reddish-brown. Ammonia, lime-water, and the alkaline {307} bicarbonates also produce a reddening, and if applied in considerable quantity a brownish tinge. It is very probable that the above-mentioned principle is applicable to the preparation of writing ink.
RIBANCOURT’S WRITING INK.—M. Ribancourt, who paid much attention to the preparation of inks, stated that none of the ingredients should be in excess. “If there be a want of the matter of galls, part of the vitriol will not be decomposed; if, on the contrary, there be too much, the vitriol will take as much as it can decompose, and the remainder will be nearly in the state of the decoction of galls, subject to change by becoming mouldy, or to undergo an alteration after writing which destroys its legibility much more completely than the change undergone by ink containing too small a portion of the galls.
“It is doubtful whether the principles of the galls are well extracted by cold maceration, and it is certain that inks made in this way flow pale from the pen, and are not of so deep a black as those wherein strong boiling is recurred to.”
From all the foregoing considertions, M. Ribancourt gives the following directions for the composition of good ink:—
“Take 8 oz. of Aleppo galls (in coarse powder); 4 oz. of logwood (in thin chips); 4 oz. of vitriol of iron; 3 oz. of gum arabic (in powder); 1 oz. of vitriol of copper; and 1 oz. of sugar-candy. Boil the galls and logwood together in 12 lb of water for one hour, or till half the liquid has evaporated. Strain the decoction through a hair sieve or linen cloth, and then add the other ingredients. Stir the mixture till the whole is dissolved (more especially the gum), after which leave it to subside for twenty-four hours. Then decant the ink, and preserve it in bottles of glass or stoneware well corked.” The sulphate of copper must be omitted in the preparation of an ink required for steel pens.
DR. BOSTOCK’S INSTRUCTIONS FOR THE MANUFACTURE OF INK.—A few years since, Dr. Bostock presented to the Society of Arts the following, valuable communication “On the Properties of Writing Inks,” which will be read with interest. {308}
“When the sulphate of iron and the infusion of galls are added together, for the purpose of forming ink, we may presume that the metallic salt or oxide enters into combination with at least four proximate vegetable principles, viz: gallic acid, tan, mucilage, and extractive matter, all of which appear to enter into the composition of the soluble part of the gall-nut. It has been generally supposed that two of these, the gallic acid and the tan, are more especially necessary to the constitution of ink; and hence it is considered, by our best systematic writers, to be essentially a tannogallate of iron. It has been also supposed that the peroxide of iron alone possesses the property of forming the black compound which constitutes ink, and that the substance of ink is rather mechanically suspended in the fluid than dissolved in it.
“Ink, as it is usually prepared, is disposed to undergo certain changes, which considerably impair its value; of these, the three following are the most important:—Its tendency to moulding; the liability of the black matter to separate from the fluid, the ink then becoming what is termed ropy; and loss of color, the black first changing to brown, and at length almost entirely disappearing.
“Besides these, there are objects of minor importance to be attended to in the formation of ink. Its consistence should be such as to enable it to flow easily from the pen, without, on the one hand, its being so liquid as to blur the paper, or on the other, so adhesive as to clog the pen and be long in drying. The shade of color is not to be disregarded; a black approaching to blue is more agreeable to the eye than browner ink; and a degree of lustre or glossiness, if compatible with due consistence of the fluid, tends to render the characters more legible and beautiful.
“With respect to the chemical constitution of ink, I may remark that, although as usually prepared it is a combination of the metallic salt or oxide with all the four vegetable principles mentioned above, yet I am induced to believe that the last three of them, so far from being essential, are the principal {309} cause of the difficulty that we meet with in the formation of a perfect and durable ink.
“I endeavored to prove this point by a series of experiments, of which the following is a brief extract.
“Having prepared a cold infusion of galls, I allowed a portion of it to remain exposed to the atmosphere, in a shallow capsule, Until it was covered with a thick stratum of mould, the mould was removed by filtration, and the proper proportion of sulphate of iron being added to the clear fluid, a compound was formed of a deep black color, which showed no further tendency to mould, and which remained for a long time without experiencing any further alteration. Another portion of the same infusion of galls had solution of isinglass added to it, until it no longer produced a precipitate; by employing the sulphate of iron, a black compound was produced, which, although paler than that formed from the entire fluid, appeared to be a perfect and durable ink.
“Lastly, a portion of the infusion of galls, was kept for some time at the boiling temperature, by which means a part of its contents became insoluble; this was removed by filtration, when, by addition of sulphate of iron, a very perfect and durable ink was produced.
“In the above three processes, I conceive that a considerable part of the mucilage, of the tan, and the extract, were respectively removed from the infusion, whilst the greatest part of the gallic acid would be left in solution.
“The three causes of deterioration in ink, the moulding, the precipitation of black matter, and loss of color, as they are distinct operations, so we may presume that they depend on the operation of different proximate principles.
“It is probable that the moulding more particularly depends ©n the mucilage, and the precipitation on the extract, from the property, which extractive matter possesses of forming insoluble compounds with metallic oxides.
“As to the operation of the tan, from its affinity for metallic salt we may conjecture that, in the first instance, it forms a {310} triple compound with the gallic acid and the iron, and that in consequence of the decomposition of the tan, this compound is afterwards destroyed. Owing to the difficulty, if not impossibility, of entirely depriving the infusion of galls of any one of its ingredients without in some degree affecting the others, I was not able to obtain any results which can be regarded as decisive; but the general result of my experiments favors the above opinion, and leads me to conclude that, in proportion as ink consists merely of the gallate of iron it is less liable to decomposition or to experience any kind of change. The experiments to which I have alluded above, consisted in forming a standard solution by macerating the powder of galls in five times its weight of water, and comparing this with other infusions, which had either been suffered to mould, from which the tan had been extracted by jelly, or which had been kept for some time at the boiling temperature, and by adding to each of these respectively both the recent solution of the sulphate of iron, and a solution which had been exposed for some time to the atmosphere.
“The nature of the black compound produced was examined, by putting portions of it into cylindrical jars and observing the changes which they experienced with respect either to the formation of mould, the deposition of their contents, or any change of color. The fluids were also compared by dropping portions of them upon white tissue paper, in which way both their color and their consistence might be minutely ascertained. A third method was to add together the respective infusions, and the solutions of the sulphate of iron, in a very diluted state, by which I was enabled to form a more correct comparison of the quantity and of the shade of the coloring matter, and of the degree of its solubility.
“The practical conclusions which I think myself warranted in drawing from these experiments are as follows:—In order to procure an ink which may be little disposed either to mould or to deposit its contents, and which at the same time may possess a deep black color not liable to fade, the galls should be {311} macerated for some hours in hot water, and the fluid filtered; it should then be exposed for about fourteen days to a warm atmosphere, when any mould which may have been produced must be removed. A solution of sulphate of iron is to be employed which has been exposed for some time to the atmosphere, and which consequently contains a certain quantity of the red oxide diffused through it. I should recommend the infusion of galls to be made of considerably greater strength than is generally directed, and I believe that an ink formed in this manner will not necessarily require the addition of any mucilaginous substance to render it of a proper consistence.
“I have only farther to add, that one of the best substances for diluting ink, if it be in the first instance too thick for use, or afterwards become so by evaporation, is a strong decoction of coffee, which appears in no respect to promote the decomposition of the ink, while it improves its color and gives it an additional lustre.”
Dr. Ure recommends the following formula for the manufacture of writing ink. To make twelve gallons take: 12lb of nutgalls; 5lb of green sulphate of iron; 5lb of gum Senegal; 12 gallons of water. The bruised nutgalls are to be put into a cylindrical copper, of a depth equal to its diameter, and boiled during three hours, with three-fourths of the above quantity of water, taking care to add fresh water to replace what is lost by evaporation. The decoction is to be emptied into a tub, allowed to settle, and the clear liquor being drawn off, the lees are to be drained. The gum is to be dissolved in a small quantity of hot water, and the mucilage thus formed, being filtered, it is added to the clear decoction. The sulphate of iron must likewise be separately dissolved and well mixed with the above. The color darkens by degrees, in consequence of the peroxidizement of the iron, on exposing the ink to the action of the air.
But ink affords a more durable writing when used in the pale state, because its particles are then finer and penetrate the paper more intimately. When ink consists chiefly of tannate {312} of peroxide of iron, however black, it is merely superficial, and is easily erased or effaced. Therefore, whenever the liquid made by the above prescription has acquired a moderately deep tint, it should be drawn off clear into bottles and well corked up. Some ink-makers allow it to mould a little in the casks before bottling, and suppose that it will thereby be not so liable to become mouldy in the bottles. A few bruised cloves or other aromatic perfume, added to ink, is said to prevent the formation of mouldiness, which is produced by the ova of infusoria animalcules.
The ink made by this prescription is much more rich and powerful than many of the inks commonly sold. To bring it to the common standard a half more water may safely be added. Even twenty gallons of tolerable ink may be made from the above weight of materials.
SCOTT’S WRITING INK.—Mr. Scott’s method of manufacturing writing ink, as patented by him in 1840, is as follows:—Take 48lb of logwood chips, and let them be saturated two days in soft water, then put the same into a close covered iron cauldron, and add 80 gallons of soft water; let these be boiled one hour and a half, when the wood must be taken out and the fluid left, to which add 48lb of the best picked Aleppo galls in coarse powder; boil these half an hour longer, then draw off the fire, and let it remain in the cauldron twenty-four hours infusing, during which it is to be very frequently agitated; when the properties of the galls are sufficiently extracted, draw off the clear fluid into a vat, and add 40lb of pulverized sulphate of iron; let these ingredients remain a week (stirring daily), after which add four gallons of vinegar. Next take 71⁄2lb of the best picked gum arabic, and dissolve it in sufficient water to form a good mucilage, which must be well strained, and then added to the fluid by degrees; let these stand a few days longer, when pour into the same 20 ounces of the concentrated nitrate of iron; let the whole stand by again until it has arrived at its height of blackness; next pour the clear fluid off from the sediment, and add to it the following substances, each prepared and ground separately:— {313}
First, take half a pound of Spanish indigo, which grind very fine between a muller and stone, adding by degrees portions of the ink until it is made into an easy soluble paste; next take well-washed and purified Prussian blue five pounds, which prepare as the former, except grinding it in distilled water in lieu of the fluid, until it is formed into a soluble paste; also next take four ounces of gas black which results from the smoke of gas burners received on surfaces of glass, as is well known, which grind in one ounce of the nitrate of iron; when each is sufficiently fine, let them remain a few hours unmixed, when the whole may be incorporated with the fluid, and kept agitated daily for a week. The clear may then be poured off for use. The above will make eighty gallons of ink.
DR. NORMANDY’S BLACK INK.—In order to supersede the use of nutgalls, Dr. Normandy patented the following process for making black ink:—
Take either sumach, elm wood, elder, chestnut, beech, willow, oak, plum, sycamore, cherry, poplar wood, catechu, or any other wood or berry, or extract of vegetable substances, containing gallic acid and tannin, or either, and put this, previously reduced to powder, into a copper full of common water, and boil it until a sufficiently strong decoction be obtained.
The quantity of water must of course vary according to the sort of vegetable substance employed; catechu, for example, requiring less water than sumach, on account of the former being almost totally soluble. To this add a certain quantity of Campeachy wood, of acetate and hydrate of deutoxide of copper, of sulphate of alumina and potash, of sulphate of protoxide of iron, in quantities which vary also according to the vegetable material first employed, and gum arabic, or the best sort of gum Senegal, in the proportion of eighty pounds or thereabouts for 340 gallons of liquid; also a variable quantity of sulphate of indigo; the whole of these last ingredients, depending on the shade of the color intended to be produced, it is impossible to indicate absolutely the proportions in which they are to be used, as the taste and fancy of the operator must {314} decide. Supposing, however, a blue black to be the color desired, and sumach, for example, the vegetable ingredient selected for the purpose, the proportions should be for 240 gallons: sumach, from 12 to 15 sacks, of four bushels each; Campeachy logwood, 2 cwt. or thereabouts, according as new or old chip is used; gum arabic, 80 lb. to 1 cwt.; sulphate of protoxide of iron, 1 cwt.; acetate and hydrate of deutoxide of copper, 4lb; sulphate of alumina and potash, 37lb; sulphate of indigo, 6lb, or even more, according to the intensity of the blue cast desired. If catechu were to be used instead of sumach, 1 cwt. would be required, the proportions of the other materials remaining the same.
The variously colored precipitates which salts of iron form in the solutions of the above-cited vegetable astringent substances, all of which precipitates vary from the green to the brown (the decoction of nutgalls yeilding with salts of iron only a dark purple,) are the obstacles which have hitherto prevented the use of these vegetable substances, with a view to supersede nutgalls; but by means of the sulphate of indigo in various proportions, from the above-cited substances a liquid may be obtained, of different shades of color, from dark blue to most intense black, applicable to dyeing, staining, or writing, and which may be used with every description of pen.
DR. NORMANDY’S PURPLE INK.—To produce a purple-colored ink called the “King of Purples,” Dr. Normandy recommends the following proportions to be observed:—To twelve pounds of Campeachy wood add as many gallons of boiling water; pour the solution through a funnel with a strainer made of coarse flannel, on one pound of hydrate or acetate of deutoxide of copper finely pulverized (at the bottom of the funnel a piece of sponge is placed), then add immediately 14lbs. of sulphate of alumina and potash, and for every 340 gallons of liquid add eighty pounds of gum arabic or gum Senegal. Let these remain for three or four days, and a beautiful purple color will be produced.
DR. NORMANDY’S BLUE INK.—Dr. Normandy’s blue ink is made by operating upon Chinese blue or cyanoferruret of {315} iron. The cyanoferruret of iron is to be ground in water with oxalic acid or bin-oxalate of potash, adding gum arabic in the following proportions: to seven ounces of water add three drachms of Chinese blue, 1 drachm of bin-oxalate of potash, and 1 drachm of gum arabic; to these ingredients a solution of tin may be added.
GIROND’S SUBSTITUTE FOR GALLS.—The substitute for gallnuts, patented by M. Girond, of Lyons, in 1825, is an extract from the shell of the chestnut, and also from the wood and sap of the chestnut-tree. The extract is denominated Damajavag, and the mode of preparing it is by reducing the chestnut-shell into small pieces, and boiling them in water.
One hundred-weight of the shells of chestnuts broken into small pieces is to be immersed in about 180 or 200 quarts of water, in a vessel of copper or any other material, except iron, and after having been allowed to soak in this water for about 12 hours, the material is then to be boiled for about three hours, in order to obtain the extract. The wood of the chestnut tree may be cut into small pieces or shaved thin, and treated in the same way.
The extract is now to be drawn off from the boiler, and filtered through a fine sieve or cloth, after which the water must be evaporated from it until the extract is reduced to the consistence of paste.
It may now be cut into cakes of any convenient size, and dried in an oven of low temperature, and when hard, may be packed for sale, and used for any of the purposes in the arts to which gallnuts have been heretofore applied. The quantity of damajavag obtained from the above will be about 8 or 10 lbs.
In using this damajavag, it is only necessary to pound or otherwise reduce it to powder when it may be mixed with other ingredients as pulverized gall nuts.
The same chemical properties belong to the sap of the chestnut-tree, which may be extracted by tapping the trunk, and when so obtained, may be used for the same purpose as gallnuts.
STEPHENS’ BLUE INK.—Stephens’ blue ink is prepared as follows:—Take Prussian blue, whether produced from a combination of prussiate of potash and salts of iron, or the Prussian {316} blue of commerce, as commonly manufactured, and put this into an earthen vessel, and pour over it a quantity of strong acid, sufficient to cover the Prussian blue. Muriatic acid, sulphuric acid, or any other acid which has a sufficient action upon iron will do. If sulphuric acid is used it should be diluted a little, that is, with a quantity of water equal to about its bulk. The Prussian blue is allowed to remain in the acid from twenty-four to forty-eight hours or longer, and then the mixture is diluted with a large quantity of water, stirring it up at the time, for the purpose of washing from it the salts of iron. When in this state of dilution, it is allowed to stand until the color has subsided, when the supernatant liquor is drawn off with a syphon and more water added to it. This process is repeated until the acid, with the iron, has been completely washed away, which is known by testing it with prussiate of potash, which will show if it yields any blue precipitate; if not, it is sufficiently washed. The product is then placed upon a filter, and suffered to remain until the liquid has all drained away.
The Prussian blue, thus prepared, is reduced to a state containing less iron than the Prussian blue of commerce, in which state it is more readily acted upon, and rendered soluble than in any other condition.
This Prussian blue may then be placed in evaporating dishes, and gently dried. To form the Prussian blue, so operated upon, into a solution, oxalic acid is added, and carefully mixed with it, after which cold water is added (cold distilled water is best) a little at a time, making it into a dense or dilute solution, according to the color required. The quantity of oxalic acid may vary according to the quantity of water used. It will be found that the Prussian blue that has undergone the process of digestion, as described, requires but a small quantity of oxalic acid to dissolve it: about one part of oxalic acid will dissolve six parts of Prussian blue, the weight taken before digesting in the acid. This will answer for a concentrated solution, but for a dilute solution more acid will be required.
(TO BE CONTINUED.)
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