516 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 

 WRITING PIGMENTS OF ANCIENT MANUSCRIPTS. 



The destruction of ancient codices and palimpsests by 

 modern scholars has been exhaustively discussed by Hotz- 

 Osterwald, of Zurich. He contends that modern philologists 

 ruin the ancient manuscripts by improper reagents, or inju- 

 dicious use of them, and asserts that, with the exception of 

 the carbon inks employed on papyrus, the writing pigments 

 of antiquity and the Middle Ages have scarcely been inves- 

 tigated. The dark to light-brown pigment universally used 

 on parchment, hitherto a problem, he contends, upon histor- 

 ical, chemical, and microscopic evidence, is identical with 

 cenocyanin, and was prepared for the most part from yeast, 

 and was first employed as a pigment. Contrary to the gen- 

 eral opinion, it contains no iron, except frequently simply ac- 

 cidental traces. After its appearance in Greece in the third 

 century, it formed almost exclusively the ink of the ancient 

 manuscripts, until displaced in the fourteenth century by 

 the gallate inks, undoubtedly introduced by the Arabians. 

 The reagents usually employed upon manuscripts are with- 

 out exception either wholly or partially objectionable. First 

 of all the well-known " Gioberti-tincture " (yellow prussiate 

 of potash and hydrochloric acid) soon converts both ink and 

 parchment into a blue powder. The metallic sulphides, gen- 

 erally pronounced perfectly harmless, also cause the writing 

 to wash, and often render it illegible in a short time. On 

 the other hand, yellow and red prussiate of potash with 

 acetic acid are recommended, and it is said that successive 

 treatment with solutions of them may be of service with 

 most perplexing palimpsests. Sulpho-cyanide of potassium, 

 however, although theoretically the best, when used with 

 acetic acid causes such decided contraction of the parchment 

 as to be useless in this way. The destruction of many old 

 manuscripts, ascribed to the monks, he feels satisfied has been 

 due to the physical properties of the papyrus, especially its 

 attraction for moisture. 13 C, March 1, 1875, 321. 



TO RESTORE OLD WRITING. 



To restore writing upon parchment, or paper, which may 

 have become faded or illegible by time, it is recommended 

 to first go over the surface with a sponge and warm water, 



