308 Conflagration of the Odeon, i^c. 



This produdion of fulphur by the calcination of plafter, in the large way, is a conftant 

 ft(ft, fimilar to that which I difcovered about twenty years fince, and is confirmed by this 

 unfortunate event. 



State on the fubftances which were found after the fire of the Odeon. 



A mafs of calcinated iron mixed with flate and brick partly vitrified. 



Hexagonal tiles and bricks changed by the fire, and mixed with black porous fcoriae and 

 an earthy yellow friable matter. 



A blackifli martial fcoria tuberculated and brilliant in its frafture. 



Cellular martial fcorias of a reddiih-brown colour, covered with a kind of white compaft 

 frit. 



Slates partly vitrified. 



Calcareous and gypfeous earth impregnated with pyrophorus and coaly liver of fulphur, 

 which gave it a blueifh colour ; this earth, though penetrated with water, being taken from 

 under the ruins, emitted a fmell of decompofed liver of fulphur, and acquired a tinge of a 

 violet from the combuftion of the fulphur. 



This earth had a flight ftyptic tafte. 



Expofed to the flame of a taper the fulphur which it contained burned very vifibly. 



A brick which had upon its top and bottom fome of this earth, coloured by the pyrophorus, 

 had been ignited to fuch a degree as to become vitrified. 



Plafter partly decompofed penetrated with liver of fulphur, which manifefted itfelf when 

 the nitric acid was poured upon it. A ftrong efFervefccnce was occafioned by the calcareous 

 earth contained in a difengaged ftate. 



An hexagonal tile covered with a yellowlfti glafs of lead : this tile was alfo impregnated 

 with liver of fulphur, as was obferved by the application of nitric acid. 



Slates partly vitrified and agglutinated, which had alTumed a reddifh colour. 



VIII. 



On the chemical J^'ion of different Metals on each other at the common Temperature eftht 



Atmojphere. By C/T. Fabroni.* 



X HE peculiar fenfation difcovered by Sultzer, and which is manifefted on the tongue 

 when touched by two metals in mutual contaft, though none is excited, when they are ap- 

 plied feparately to this organ, is ranked among the galvanic phenomena. Cit. Fabreni, far 

 from attributing thefe effedls to an alraoft unknown agent, fuch as the eleftrical fluid, is- 

 of opinion that they depend on a chemical operation, in the fame manner as the fenfation 

 of tafte moft probably does. He endeavours to prove this by a number of obfervations and 

 experiments. 



* Communicated to the Philom. Society at Paris, Bulletin, Thermidor VII. No. 29. 



He 



