Proceedings of the British Association. 47 



Account of a new compound of arsenious and sulphnric acids ; 

 by Dr. Schafhaeutl. This was obtained from the escaping 

 smoke of copper calcining furnaces near Swansea, in South 

 Wales. The new compound was another singular instance 

 where an anhydrous crystallized body was deposited under the 

 presence of water only, and was a remarkable proof of the un- 

 limited number of different forms of combination which might 

 be produced even in inorganic substances in contact under vary- 

 ing circumstances. The copper ores smelted in South Wales 

 were chiefly copper pyrites, mixed with iron pyrites, gray copper 

 ore, &c. ; in fact, a mixture in which the sulphurets of copper, 

 iron, arsenic, antimony, cobalt, nickel, zinc and tin were invaria- 

 bly found together. The sulphur and arsenic escape from these 

 ores during the calcining process, as sulphurous and arsenious 

 acids, and have been found to destroy all vegetation for miles 

 around the copper works, without affecting animal life in the 

 slightest degree. By bringing the escaping fumes in contact 

 with steam, and forcing it through burning charcoal, or subject- 

 ing it only to a great pressure in contact with steam, the new 

 solid compound was deposited on the cool surfaces of the cham- 

 bers connected with the calcining furnace. It was deposited in 

 beautiful crystallized leaves or tables, perhaps belonging to the 

 same class as Wohler's dimorphic modification of the crystalliza- 

 tion of arsenious acid, the regular form of which belongs to the 

 octahedron. It was found to consist of 



Arsenious acid, 68.250 



Sulphuric acid, ----- 27.643 

 Protoxide of iron, - , - - 3.029 



Oxide of copper, - - . . 0.420 



Oxide of nickel, . _ _ _ 0.656 



99.998 

 These crystals attracted moisture from the air with great ra- 

 pidity and with evolution of heat, corroding animal and vegeta- 

 ble substances as powerfully as concentrated sulphuric acid. One 

 of the remarkable changes during the formation of this com- 

 pound, was the conversion of sulphurous acid into sulphuric acid, 

 as well as the presence of iron, copper, and nickel, in a deposit 

 from gaseous matter. No other definite compound of arsenic 

 acid with another acid seems to be known, except those with the 

 organic tartaric and paratartaric acids. 



