172 Scientific Intelligence. 



ty muriate of manganese can be made slowly, and is consequently 

 more certain. — Bib. Univ. Juin, 1828. 



9. JVew indelible ink, by Henry Braconnot. — This enterprising 

 chemist describes an ink, which, agreeably to his account of its pro- 

 perties, will prove to be a valuable accession to the arts of writing, 

 marking, and dyeing. 



Being engaged, conjointly with M. Parisot de Nancy, in the pro- 

 duction of a cheap and solid brown dye, he torrified with potash, vari- 

 ous organic matters, and thus ascertained that substances containing 

 the most azote, such as flesh, leather, horns, &c. gave the deepest 

 color. From a hint, also, which they derived from Fourcroy, he 

 was induced to add to the mixture, prior to torrefaction, flowers of sul- 

 phur, and by this means they produced a deep chesnut brown, more 

 substantial than any like color known to the dyer. 



The proportions which he found most convenient, and the method 

 of proceeding were to dissolve 20 parts of Dantzick potash in boiling 

 water, and add to the solution 10 parts of animal matter, minutely 

 divided, (leather parings from the tanners were found to be conven- 

 ient,) and 5 parts of flowers of sulphur. These are boiled to dryness 

 in a cast iron pot, and the heat is urged until the mixture softens, tak- 

 ing care to prevent ignition, and, after adding by degrees a suitable 

 portion of water, the fluid portion is filtered through a loose cloth. 

 There is thus produced a deep colored dye or ink which can be easi- 

 ly preserved in a well stopped botde. A single pen full of this ink 

 is said to be sufficient to write one or two quarto pages, and that it 

 possesses all the desired properties of an indestructible ink, flowing 

 more fireely from the pen than common ink, and resisting the most 

 powerful chemical agents. 



A strip of paper written with this liquid, treated with a concen- 

 trated solution of boiling caustic potash, was mostly destroyed, but 

 the scraps which escaped destruction, plainly showed the letters in 

 their perfect shapes. Paper, written with the same liquor, immersed 

 for an instant in moderately concentrated sulphuric acid, was dissolv- 

 ed, passing in part to the condition of gum, but on the thin undis- 

 solved portion, the writing might easily be read. 



The characters of this liquor, experienced no change in twenty 

 four hours, in concentrated nitric acid, even assisted by heat, to an 

 extent not quite sufficient to destroy the paper entirely. 



