[ 121 ] ^ 



XVI. Chemical Examination of some Antiquities found in the 

 Vicinity ofBrool^ on the Rhine. By Dr. Rudolph Brandes. 



'T'HE importance of the vicinity of Brool to the antiquarian 

 is sufficiently known, as well as the great discoveries made 

 there by the diligence of M. Dorow. It was through his 

 kindness that I obtained the antiquities considered in this me- 

 moir, with the request to analyse them as speedily as possible; 

 a request, however, which I have not been able to fulfill until 

 now. 



I. A Fragment of Roman Glass found near Brool. 

 The invention of glass is known to be very ancient ; never- 

 theless few antique remains of it have come down to us, or 

 have been analysed. 



Although the art of manufacturing glass was not carried to 

 that degree of perfection among the ancients to which it has 

 been brought in our days, still in some branches of it they 

 liad gone very far, as has been sufficiently shown by the learned 

 investigations of Winkelmann. 



The piece of glass which I obtained from M. Dorow was 

 a fragment of a round vase, and weighed about 10 grains. Its 

 colour was of a milky-white with a very blueish cast. A pel- 

 licle of a brilliant gold-colour covered its exterior, and in part 

 its interior surface. This had so much the appearance of 

 gilding, that without a chemical trial one would have taken it 

 to be gold ; but I shall show below that this was not the case; 

 The long period of time during which the glass had been ex- 

 posed to the effects of the air, water, and the pressure of the 

 earth, had made a visible impression on it; so much so, that 

 it was in a mouldering state, had entirely lost its firmness and 

 brittleness, and when broken, pressed, or scraped, fell into 

 small leaves like mica. It had completely lost its transparency; 

 but it was still evident, from its appearance in the centre, that 

 it was originally perfectly transparent, that part, from havuig 

 somewhat resisted the destructive effects that had acted upon 

 the rest, being so still. Wherever the glass was covered with 

 the gold-like pellicle it was not transparent, but where free 

 fiom it, it was i)erfectly clear. 



By endeavouring to separate that covering, no gold-leaf was 

 detached, but thin leaves of glass ; and the surface beneath soon 

 offered a similar apiieurance. In some places that metallic 

 tarnish assumed a fine blueish, red, or green hue; and a si- 

 milar appearance was produceil by taking oft' the apparently 



• From Schwei^'gcr's Journal, Band x. [). 304, 



Vol. GG. No. 328. Aug. 1825. Q metallic 



