FABRICATION OF SULPHURIC ACID. 41 



floor washed in a decoction of the cucumis colocynthin, which 

 I am told is poisonous to them. Your correspondent, if he 

 pleases, may rub his body with it — it is perfectly safe ; or 

 he may put into his bed a bunch of fresh rue or savin, or 

 perhaps of any other strong smelling herb. 



VIII. 



Theory of the Fabrication of Sulphuric Acid; read in the 

 Class of Physical and Mathematical Science.? of the French 

 National Institute, January the 9.0th, 1 806, by Messrs. 

 Desormes and Clement.* 



UlFFERENT opinions are entertained respecting the Nitrate sup- 

 utility of nitrate of potash in the usual mode of fabricating crease \h\ tenv- 

 sulphuric acid. Some believe, that the high temperature perature, 

 produced by its deflagration determines the formation of 

 sulphuric acid; others imagine, that the nitrate affords the afford oxigen, 

 quantity of oxigen necessary to complete the combustion, c ' 

 which the atmospheric air has commenced: others again 

 suppose, that, water may be decomposed in the process, &c. 

 We shall here attempt only the refutation of the first and 

 second of these hypotheses, which appear at first sight the 

 most probable. 



The first cannot be maintained, because, at the same time Temperature 



as nitrate of potash is added to the sulphur, clay and water ' lot incre f- d » 



1 . because clay- 



are frequently mixed with it, each of which has the effect and water are. 

 of diminishing the temperature; one by rendering the com- P resent - 

 bustion more slow ; the other by constantly absorbing a 

 Jarge quantity of the caloric evolved, to acquire the state 

 of vapour. Besides, it is known, that sulphur burnt by 

 itsdf, at a temperature of 1000° of the centigrade thermo- 

 meter for instance (1832° F.) affords no trace of sulphu- 

 ric acid. 



The other hypothesis, which does not appear so remote Oxigen of the 

 from the truth, is notwithstanding equally erroneous. IfcJJ^nJert riw 

 admits, that the oxigen extricated from the nitrate of pot- sulphurous acid 

 ash is sufficient for the conversion of all the sulphureous 111 ' sul P hunc - 



" * An. de Chim. Vol. LIX. p. 329, Sept. 180G. 



acid 



