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LV. TVere the Ancient Egyptians acquainted with Nitric Acid ? 

 By Thornton J. Herapath, Esq."^ 



IN the Supplement Number of the Philosophical Magazine 

 for July last, my father published a paper on " Early Egyp- 

 tian Chemistry," in which he gave a short account of some expe- 

 riments he had made on certain hieroglyphical marks or letters 

 that had been discovered on the wrappers of a mummy which was 

 recently unrolled by Mr. Nash at this Institution ; and he then 

 stated it was his belief that the ancient Egyptians were acquainted 

 with a marking-fluid containing nitrate of silver for its basis, 

 and were also familiar with the use of nitric acid. A short time 

 afterwards, Mr. Denham Smith, in a reply to this letter, took 

 exception to my father's views on the subject ; and whilst admit- 

 ting the interesting nature of the discovery that had been made of 

 an argentine solution having been employed some three thousand 

 years ago as ^marking-ink,' totally dissented from the conclusions 

 that had been founded on it, inasmuch, he said, as there was no evi- 

 dence to prove that the Egyptians were even acquainted with the 

 art of distillation. He also hazarded the opinion, unsupported, 

 however, by direct evidence, that the marking-fluid in question 

 was prepared — if I understand him aright — by dissolving either 

 the chloride or oxide of silver in an ammoniacal solution, and 

 consequently without the intervention of any acid whatever. As 

 the question in dispute is one of considerable interest in a 

 scientific point of view, I determined to subject the marks to a 

 fresh examination. After making several preliminary experi- 

 ments, I found that no results of any value could be obtained by 

 the ordinary modes of analysis, and was therefore compelled, as 

 a last resource, to call in the assistance of the microscope. 



Upon examining some of the fibres of the bandages that were 

 stained by the argentine ink, I found them to present a very 

 peculiar appearance. The ends nearest the corroded parts of the 

 fabric were stained of a deep brown or black ; but for some little 

 distance beyond the blackened portion the fibre was coloured of 

 a pale yellow hue, as if, during the decomposition of the silver 

 salt that had been employed as ' marking-ink,' the nitrogenous 

 constituents of the tissue had been partially acted upon and con- 

 verted into xanthoproteic acid. 



Between several of the fibres, and in many places adhering to 

 their external surfaces, were found small particles of some organic 

 tissue, which were coloured of a still deeper yellow than the 

 fibres themselves. On subjecting some of the latter to the action 

 of strong liquor ammonicB, the yellow portions, particularly the 



* Read before the Bristol Microscopical Society, and now communicated 

 by the Author. 



