AMERICAN Institute. 425 



American Institute, Polytechnic Association, 



May 11, 1859. 



John Johnson, Esq., Chairman. Henry Meigs, Esq., Secretary. 

 Mr. Meigs read the following paper Upon the subject selected last evening, 

 Viz. : 



INli — WRITING INK. 



"The writing ink of the ancients differed materially from ours. They 

 used charcoal, with some adhesive or mucilaginous matter, and their ink was 

 far more durable tlian most of our modern inks. Now we form a chemical 

 instead of a mechanical compound. We use as a basis proto-gallate of iron, 

 and proto-tannate of iron, which together, by oxydation, become per-gal- 

 late and per-tannate. The color is at first pale, but oxygen soon darkens 

 the writing. 

 i_ " Brande says that the following recipe for writing ink is good : 



"Aleppo galls, well bruised, 6 ounces ; sulphate of iron, 4 ounces; gum 

 arable, 4 ounces ; water, 6 pints. 



"Boil the galls in water, and then add the other ingredients. Put the 

 whole in a bottle, well stopped, and shake it occasionally. After two 

 months, strain it off, and add to it one grain of corrosive sublimate or three 

 drops of creosote for each pint. This will hinder its moulding." 



" He also says, that the great object is to regulate the proportion of the 

 sulphate of iron to the galls. Time should elapse between the mixture 

 ^nd the using. Also gum suspends the coloring matter, prevents too great 

 fluidity, and protects the vegetable matter from decomposition. Logwood 

 and other vegetable dyes do not give a permanent ink. Lastly when ink 

 ha.s b'ecome so pale as to be almost illegible when written with, it may be 

 partially restored by applying infusion of galls to it." 



SYMPATHETIC INK, 



Is made of metallic solutions, writings made with which are illegible in 

 ordinary temperatures, but are rendered legible .by the application of heat. 



red INK. 



According to Heusler's receipt, is made of, Brazil wood, 2 ounces ; mu- 

 riate of tin, 4 drachm ; pulverized alum, ^ drachm ; gum arable, 1 drachm ; 

 water, 32 ounces. These ingredients are to be boiled until the quantity 

 is reduced one-half. 



Carmine and ammonia make a beautiful red ink, but it is fugitive 



INDELIBLE INK FOR LINEN. 



Nitrate of silver, one ounce ; water, one ounce. Thicken when cold, 

 with a little mucilage. 



The place to be written upon, is first moistened with carbonate of soda 

 liquor, and then dried, when it is fit to receive the writing. 



A marking ink which can be used without the soda is composed of am- 

 moniated solution of nitrate of silver, thickened with a little mucilage. 



A black indelible ink, is formed as follows: best lampblack, 10 grains; 

 indigo, 2 grains. Dissolve in four ounces of acetic solution of pure gluten, 



