Ixx NOTES. 



the works in the salt-clay of Wallein and Berchtholdsgaden ; where the chambers 

 become filled with gases which extinguish burning lights? Or do elastic gases, 

 in a state of tension, in flowing out, prevent the entrance of atmospheric air?" 

 I wrote these questions down, fifty-three years ago, at Turbaco. According to 

 the latest observations of M. Vauvert de Me'an (1854), the inflammability of 

 the gas exhaled has quite maintained itself. This traveller has brought back 

 samples of the water which fills the little crater-orifices of the volcancitos. 

 Boussingault found in a " litre" of it 6 r '59 of common salt; carbonate of soda, 

 0'31; sulphate of soda, 0'20; and also traces of borate of soda and iodine. 

 In the sediment deposited, Ehrenberg, by exact microscopic examination, re- 

 cognised no calcareous particles, and nothing belonging to scoriae; but grains of. 

 quartz, mixed with laminae of mica and many small crystalline prisms of black 

 augite, as it often presents itself in volcanic tufa; no trace of silicified sponges 

 or of poly gastric infusoria, nothing indicating the neighbourhood of the sea; but, 

 on the other hand, many remains of dicotyledonous plants, and of grasses, and 

 parts of lichens, reminding us of the constituents of the Moya of Pelileo. 

 Whereas Ch. Sainte-Claire Deville and Georg Bornemann found, in their fine 

 analysis of the Macalube di Terrapilata, O99 of carburetted hydrogen in the gas 

 emitted ; the gas which rises in the Agua Santa di Limosina near Catanea gave 

 them, as was formerly the case at Turbaco, 0'98 of nitrogen, without any trace 

 of oxygen. (Comptes-rendus de 1'Acad. des Sc. t. xliii. 1856, p. 361 and 366.) 



( 29G ) p. 214. Humboldt, Vues des Cordilleres et Monumens des Peuples 

 indigenes de I'Ame'rique, PI. XLI. p. 239. The fine drawing of the volcancitos 

 of Tnrbaco, from which the plate was engraved, was by my then young travel- 

 ling companion Louis de Rieux. On the ancient Tarruaco, in the earliest times 

 of the Spanish Conquista, see Hen-era, Dec. 1, p. 251. 



( 297 ) p. 215. Lettre de M. Joaquin Acosta a M. Elie de Beaumont, in the 

 Comtes-rendus de 1'Acad. des Sc. t. xxix. 1849, p. 530 534. 



C 298 ) p. 216. Humboldt, Asie Centrale, t. ii. p. 519 540, chiefly from 

 extracts taken from Chinese works by Klaproth and Stanislas Julien. The old 

 Chinese method of rope-boring, which, in the years 18301842, was on several 

 occasions employed with advantage in coal-mines in Belgium and Germany, had 

 been described (as Jobard discovered), in the seventeenth century, in the Relation 

 de 1'Ambassadeur Hollandais, Van Hoorn; but the most exact account of this 

 method of boring the Ho-tsing (fire-wells) was given by the French missionary 

 Imbert, who resided for many years at Kia-ting-fu. (Annales de 1' Association de 

 la Propagation de la Foi, 1829, p. 369 381.) 



(2") p. 217. According to Diard, Asie Centrale, t. ii. p. 515. Besides 

 the mud-volcanos at Damak and Surabaya, there are also, on other islands of 



