SALSES. 217 



to (from Parrot's Keports), that "the gas of the mud- 

 volcanoes of the peninsula of Taman in 1811 had the 

 property of preventing combustion, as a glowing chip was 

 extinguished in the gas, and even the ascending bubbles, a 

 foot in diameter, could not be ignited at the moment of 

 their bursting," whilst in 1834, Gobel saw readily inflam- 

 mable gas burning with a bluish flame at the same place, 

 leads me to believe that the emanations undergo chemical 

 changes in different stages. Yery recently Mibscherlich has, 

 at my request, determined the limits of inflammability of 

 artificially prepared mixtures of nitrogen and hydrogen 

 gases. It appeared that mixtures of 1 part of hydrogen 

 gas and 3 parts of nitrogen gas, not only took fire from a 

 light, but also continued to burn. When the quantity of 

 nitrogen gas was increased, so that the mixture consisted oi 

 1 part of hydrogen and 3J parts of nitrogen, it was still 

 inflammable, but did not continue burning. It was only 

 ivitk a mixture of\ part nf hydrogen and 4 parts of nitrogen 

 gas tliat no ignition too place. The gaseous emanations, which 

 from their ready inflammability and the colour of their 

 flame are usually called emanations of pure and carburetted 

 hydrogen, need therefore consist quantitatively only of one- 

 third part of one of the last-mentioned gases. With mix- 

 tures of carbonic acid and hydrogen, which occur more 

 rarely, the limits of inflammability prove different again, 

 on account of the capacity for heat of the former. Acosta 

 justly suggests the question: "Whether a tradition dis- 

 seminated amongst the inhabitants of Turbaco, descendants 

 of the Indios de Taruaco, according to which the Volcancitos 

 formerly all burnt; and were converted from Volcanes de 

 fucgo into Volcares de agua, by being exorcised and sprinkled 

 with holywater by a pious monk 72 , may not refer to a con- 

 dition which has now returned ?" Single great eruptions of 

 flames from mud volcanoes, which both before and since 

 have been very inactive (Tainan, 1793 ; on the Caspian 

 Sea, near Jokmali, 1827; and near Baklichli, 1839; near 



72 Humboldt, Vues des Cordilleres et Monuments dcs pcuples indigenes 

 de I'Amerique, pi. xli, p. 239. The beautiful drawing of the Volcancitos 

 de Turbaco, from which the copperplate was engraved, was made by my 

 young fellow-traveller, Louis de Rieux. Upon the old Taruaco in the 

 first period of the Spanish Conquista, see Herrera, Dec. i, p. 251. 



