80 J. A. Phillips, Esq., on the Metals and 



of king Menelaus as glittering with gold, electrum, silver, 

 and ivory. This alloy, though sometimes made by the direct 

 mixture of the two metals, was, doubtless, in most instances, 

 a natural production, as many gold ores also contain a cer- 

 tain portion of silver, and the ancients being apparently 

 ignorant of the method of separating them, and without any 

 knowledge of the stronger acids,* might have been in the 

 habit of occasionally adding a certain quantity of silver to 

 specimens of gold which already contained a proportion of 

 that metal, thereby converting it into electrum, in preference 

 to allowing it to remain as impure gold. 



That silver was formerly, as at the present day, chiefly 

 extracted from the ores of lead, we are distinctly informed 

 by the author of the "Historia Naturalis," who adds, that 

 those ores of silver which do not contain lead or an ore of 

 lead, cannot be successfully worked without the addition of 

 either one or the other. Tin and lead he seems to regard 

 as only two varieties of the same metal, as he describes them 

 under the title of white lead, and black, and states that the 

 white lead, called in Latin Plumbum candidum, and by the 

 Greeks, Cassiteros, was much more valuable, and commanded 

 a higher price than the black variety. 



His description of the Plumbum candidum, and the state 

 in which it was found, leaves no doubt that this much- valued 

 metal was tin, it being represented as occurring among sand, 

 in the dried-up beds of rivers, and as only known from the 

 other substances with which it was found associated by its 



* Nitric acid is first mentioned by Geber, who lived in the eighth century. He 

 describes it under the name of" dissolving water," and prepared it by distillingin 

 a retort one pound of sulphate of iron of Cyprus, half a pound of saltpetre, and a 

 quarter of a pound of alum of Tameni. This process, although not economical, 

 would certainly produce nitric acid, and to this, when obtained, he added sal- 

 ammoniac, in order to give it the property of dissolving gold. Raymond Lully, 

 who lived in the early part of the thirteenth century, employed the same pro- 

 cess, except that he omitted the alum. Basil Valentine, who was born about 

 the year 1400, describes a method of obtaining " Spirits of Nitre," by distilling 

 nitrate of potash with powdered porcelain or clay, with which the potash en- 

 tering into combination, the same result is obtained as by the former method. 

 Basil Valentine is also the first who describes oil of vitriol, which he prepared 

 by distilling sAlphate of iron according to the method at present practised at 

 Nordhausen, in Saxony. 



