SALSES. 215 



in modern geognosy and chemistry, made the remarkable 

 observation that at present " the cones diffuse a bituminous 

 odour ;" (of which no trace existed in my time) ; " that some 

 petroleum floats upon the surface of the water in the small 

 orifices, and that the gas pouring out may be ignited upon 

 every mud-cone of Turbaco." Does this, asks Acosta, indi- 

 cate an alteration of the phenomena brought about by 

 internal processes, or simply an error in the earlier experi- 

 ments ? I would admit the latter freely, if I had not 

 preserved the leaf of the journal on which the experiments 

 were recorded in detail, 71 on the very morning on which 



Turbaco is such as you have described ; there is the same luxuriance 

 of vegetation, the same form of cones of clay, and the same ejection 01 

 liquid and muddy matter ; nothing has changed, unless it be the 

 nature of the gas which is evolved. I had with me, in accordance 

 with the advice of our mutual friend, M. Boussiugault, all that was 

 necesssary for the chemical analysis of the gaseous emanations, and even 

 for making a freezing mixture for the purpose of condensing the aqueous 

 vapour, as the doubt had been expressed to me that nitrogen might 

 have been confounded with this vapour. But this apparatus was by 

 no means necessary. As soon as I arrived at the Volcancitos, the dis- 

 tinct odour of bitumen set me in the right course; I commenced by 

 lighting the gas upon the very orifice of each small crater. Even now 

 one sees on the surface of the liquid, which rises intermittently, a deli- 

 cate film of petroleum. The gas collected burns away entirely, without 

 any residue of nitrog-en(?) and without depositing sulphur (when in 

 contact with the atmosphere). Thus the nature of the phenomenon has 

 completely c/tanr/ed since your journey, unless we admit an error of obser- 

 vation, justified by the less advanced state of experimental chemistry 

 at that period. I no longer doubt that the great eruption of Galera 

 Zamba, which illuminated the country in a radius of 100 kilometres 

 (62 miles), is a salses-like phenomenon, developed on a great scale, since 

 there exist hundreds of little cones, vomiting saline clay, upon a surface 

 of 400 square leagues. I propose examining the gaseous products of 

 the cones of Tubara, which are the most distant salses from your 

 Volcancitos of Turbaco. From the powerful manifestations which have 

 caused the disappearance of a part of the peninsula of Galera Zamba, 

 now become an island, and from the appearance of a new island raised 

 from the bottom of the sea in 1848, and which has since disappeared, 

 I am led to think that it is near Galera Zamba, to the west of the delta 

 of the Rio Magdalena, that the principal focus of the phenomenon of 

 salses in the province of Carthagena is situated" (from a letter from 

 Colonel Acosta to A. von Huinboldt, Turbaco, 21 December, 1850). 

 See also Mosquera, Memoria politica sobre la Nueva Granada, 1852, 

 p. 73 ; and Lionel Gisborne, The Isthmus of Darien, p. 48. 



71 During the whole of my American expedition I always adhered 

 strictly to the advice of Yauquelin, under whom I worked for some time 



