[ i-'90 T 



LII. Chemical Exannnat'ion of an anflent Speculum. By 

 Professor KLaproth, <f Berlin *. 



JL hat the history of the antient nictalkirgy depends on a 

 proper cxphtuatiou of the different passages relating to it, 

 which .arc to he found in antient authors, requires very 

 little proof. Thoiigli various men of learning who have 

 made this point tlie"particular object of their research have 

 collected tjiese scattered fragments, and have endeavoured 

 to exhibit them in a more conspicuous poiiit of view by ar- 

 ranging them in order, every thing belonging to this sub- 

 ject has not yet been properly cleared up ; and, notwith- 

 standing the diligence of the' old philologists, many cir- 

 cumstances are still leffin a state of doubt and obscurity,^ 

 the cause of which seems chiefly to be the insufliciency of 

 tlie means employed for that purpose. On the other hand, 

 the critics and antiquaries of the present day arc in posses- 

 sion of many helps which were wanting to the former ; and 

 in this respect chemistry and mineralogy may be considered 

 as of the greatest utility when it is necessary to determine 

 the nature and component parts of the antient metals. 



Under a conviction that every contribution towards en- 

 larging our knowledge of these conipositi(ms is of consi- 

 derable importance, I have already directed my attention to 

 the numismatic part of the antient metallurgy, and given 

 ^» account of the result of the experiments I made to dc- 

 leriiiine the alloys which the Greeks and Romans employed 

 for their earlier coins f. The object of the present essay is, 

 tliie chemical examination of the metallic mass of an antient 

 speculum. Wlien tlie wants of mankind were increased 

 in consequence of their improved state of civilization, that 

 natural mirror the smooth surface of a piece of water w as 

 no longer sufficient; artilicial speculums which they might 

 always have :it iiand, and which they could use with more 

 convenience, became indispensably necessary. The only 

 materials which they could employ to qonstruct them were 

 metals ; for as soon as men l:cgau to work them they could 

 not help obscrv'iiiff and turning to advantage their suscepti- 

 bility of a fine polish, which exhibited a distinct image of 

 such objects as were presented to them. 



I do not know v/hcther there be any mention of metallic 

 mirrors earlier than that in Kxod. c. xxxviii. v. 8., \»herc 



• From ^Q\\erct\ AU^emeinfs Journal der Cbemic, No. 33. 

 t Si c itHjff 256 of I his volunii'. 



Vt^TrXVIlTNiTfiS. T ^ve 



January 1804. 



