CHEMICAL SCIENCE. 321 



discovered the mode of preparation of the so-called alzarine-ink, which is 

 particularly useful, he was anxious to prepare it in a form which would 

 allow it to be sent to a great distance and at any time of the year, render its 

 transport convenient, and diminish its cost considerably, but, at the same 

 time, fulfil all the requirements of an excellent article. This is attained by 

 the dry alizarine ink in cakes. The "ink-powders " hitherto found in com- 

 merce arc not to be compared with it, for they not only possess a different 

 composition, but never dissolve completely to form a clear solution in water, 

 and their employment is attended with so many inconveniences and disad- 

 vantages, that they have been given up. Common black ink may indeed be 

 evaporated to dryness, but it leaves a residue which does not again dissolve 

 completely in water, and never furnishes a useful ink by this solution. The 

 recipe for the preparation of the cake ink is as follows : 



Forty-two parts of Aleppo galls and three parts of Dutch madder are ex- 

 tracted with a sufficient quantity of hot water ; the fluid is then filtered, five 

 and a half parts of sulphate of iron ore dissolved in it, and two parts of a 

 solution of iron in wood-vinegar, with one and one-fifth part of solution of 

 indigo, arc added to it. The mixture is evaporated to dryness at a mode- 

 rate heat, and formed into cakes of a proper size (for instance five inches 

 long, three and a half inches broad, and three-eighths of an inch thick). 



One part of this cake-ink dissolved in six parts of hot water, furnishes 

 an excellent writing and copying ink, whilst even with one part of cake ink 

 and ten to fifteen parts of water, beautiful writing inks are obtained. Mit- 

 theil. des Gewerbe-vereins fiir das Konifjr. Hannover. 



A. copying ink, for printing with the ordinary copying press, giving off an 

 impression analogous to that of writing ink, has recently been introduced in 

 England. The ink is made of ground nutgalls, fourteen pounds ; of sul- 

 phate of iron, six pounds ; of gum Senegal, twelve pounds ; of soap, three 

 pounds ; of molasses, four pounds ; of Prussian blue, three pounds, and of 

 filtered rain fifteen gallons. The nutgalls are boiled three hours in the 

 water, and the clear liquid drawn off. The gum and sulphate of iron are 

 then separately dissolved in the water, and the whole is mixed Avith the 

 nutgall decoction, and exposed for about three weeks to the atmosphere, 

 when the liquid is drawn off from the deposited matters and sediment. The 

 molasses and soap are now added to the fluid, and the whole evaporated in 

 a water bath, to nearly the consistency of ordinary printing ink, and the 

 lampblack and Prussian bine are then mixed with it. The above ingredi- 

 ents form a black ink ; but any other color may be obtained by using cor- 

 responding coloring material s. 



Dr. Ely recommends the following method of preparing ink : A decoc- 

 tion is made with a pound and a quarter of nutgalls, and as much hot water 

 as will give five pounds of liquid af.cr straining. Then four ounces of in- 

 digo powder is mixed with half a pound of sulphuric acid, the mixture left 

 for twenty-four hours, then dissolved in five pounds of water and eir'it 

 ounces of powdered chalk, and eight ounces of iron filings added. A part 

 of the acid is neutralized by the chalk, and a part by the iron filings, forming 

 sulphate of iron. The solution thus obtained, mixed with the decoction of 



