108 On Mr. Ivory'i Table of Refractions. 



than to be able to refer to it afterwards in treating of the con- 

 stitution of the atmosphere. 



February 8, 1855. JamES IvollY. 



XIX. Analysis of the IVater of the Rio Vinagre, in the Andes 

 of Popayan, by M. Matiiano de Rivero; with gcognostic 

 and physical Illustyations of some Phenomena 'dohich are ex- 

 hibited by Sulphur, Sulphuretted Hydrogen, and Water, in 

 Volcanos. By M. A. de Humboldt. 



[^Extract (fa Letter dated the Sth October 1823.] 



"¥N compliance Avith the desire of M. de Humboldt, I pro- 

 -^ cured some of the water of Rio Vinagre. It was sent to 

 me by M. Torres, who takes an interest in all tluit can con- 

 tribute to ibcienlific researches. Tliis water has yielded |)er 



litre: 



