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Art. XII. Selections from Foreign Science. 

 I. Researches on the Sulphuric Acid of Nordhausen, by M. BussY. 



The Society of Pharmacy of Paris proposed various questions 

 relating to this acid as the subject of a prize ; most of which have 

 been well answered by the researches of M. Bussy, of which the 

 following is an account : 



The first question related to the true nature of the Sulphuric Acid 

 of Nordhausen. This acid as it exists in commerce is brown, of a 

 variable density, not much different from that of common sulphuric 

 acid, having a decided odour of sulphurous acid, and giving off 

 white suffocating vapours in the air. If heated, it boils at 100° 

 cr 120° Fahr. ; and by degrees one part evaporates in dense 

 vapours, the remainder ceases boiling, becomes colourless, and 

 is common sulphuric acid. A portion of the fuming acid was put 

 into a tubulated retort, the beak of which had been considerably 

 lengthened and drawn out in the lamp, and contracted at the aper- 

 ture : the extremity was introduced into a long narrow tube closed 

 at one end and serving for a receiver : this arrangement was made 

 to avoid the use of corks, and the access of the atmosphere. The 

 tube was then cooled by ice, and the acid heated ; it soon boiled, 

 the tube became filled with vapours which condensed into a 

 solid mass having the following properties : it was opaque, 

 white, solid, difficult to cut, and fuming in the air ; left in the air 

 it deliquesced and became like oil of vitriol ; it charred vegetable 

 substances, as paper, S^c; and when put into water dissolved with 

 a hissing noise, producing an acid solution with all the characters 

 of diluted sulphuric acid. 



These characters seemed to indicate concrete sulphuric acid : in 

 order to ascertain whether water caused the liberation of any gas, 

 the substances were mixed in a tube over mercury, but no gas 

 was liberated. It was then combined directly with a base, 

 being sublimed from the tube in which it was received, over 

 caustic baryta placed in a second tube and heated : great incan- 

 descence was produced by the combination, but no liberation of 

 gas ; on the contrary, the mercury which closed the apparatus 

 was pressed inwards. When the action was over, the barytes was 

 taken out and digested in muriatic acid ; it liberated neither sul- 

 phurous acid gas nor sulphuretted hydrogen ; it merely dissolved 

 the excess of baryta, and left a true sulphate of baryta. It fol- 

 lows, therefore, tliat the concrete acid was ])ure sulphuric acid, and 

 that no sulphurous acid was present : all that can be supposed, is 

 the presence of a little water, and this would be detected by a 

 similar experiment made with known quantities of the substances. 

 Much care was found requisite in making this experiment, espe- 

 VoL. XVIIJ. L 



