216 COSMOS. 



they were made. I find nothing in them that could make 

 me at all doubtful now ; and the observation already referred 



before my voyage : to write down and preserve the details of every 

 experiment on the same day. From my journals of the 17th and 

 18th April, 1801, I here copy the following : " As, therefore, the gas 

 showed scarcely 0.01 of oxygen from experiments with phosphorus 

 and nitrous acid gas, and not 0.02 of carbonic acid with lime-water, the 

 question is, what are the other 97 hundredths? I supposed, first of all, 

 carburetted and sulphuretted hydrogen ; but no sul phur is deposited 

 on the margins of the small craters in contact with the atmosphere, 

 and no odour of sulphuretted hydrogen was to be perceived. The pro- 

 blematical part might appear to be pure nitrogen, for, as above men- 

 tioned, nothing was ignited by a burning taper ; but I know, from the 

 time of my analyses of fire-damp, that a light hydrogen gas, free from 

 any carbonic acid, which merely stood at the top of a gallery did not 

 ignite, but extinguished the pit candles, whilst the latter burnt clearly 

 in deep places, when the air was considerably mixed with nitrogen gas. 

 The residue of the gas of the Volcancitos is, therefore, probably to be 

 regarded as nitrogen, with a portion of hj'drogen gas, the quanti- 

 tative amount of which ,we do not at present know. Does the same 

 carbonaceous schist that I saw further westward on the Rio Sinu, or 

 marl and clay, lie below the Volcancitos ? Does atmospheric air penetrate 

 through narrow fissures into cavities formed by water and become de- 

 composed in contact with blackish gray loam, as in the pits in the 

 saline clay of Hallein and Berchtholdsgaden, where the chambers are 

 filled with gases which extinguish lights ? or do the gases, streaming out 

 tense and elastic, prevent the penetration of atmospheric air?" These 

 questions were sf't down by me in Turbaco 53 years ago. According to 

 the most recent observations of M. Vauvert de Mdan (1854) the inflam- 

 mability of the gas emitted has been completely retained. The traveller 

 brought with him samples of the water which fills the small orifice of 

 the craters of the Volcancitos. In this Boussingault found in the litre: 

 common salt, 6.59 gr. ; carbonate of soda, 0.31; sulphate of soda, 0.20; 

 and also traces of borate of soda and iodine. In the mud which had 

 fallen to the bottom, Ehrenberg, by a careful microscopic examination, 

 found no calcareous parts or scoriaceous matter, but quartz granules 

 mixed with micaceous laminre, and many small crystalline prisms of 

 black Augite, such as often occurs in volcanic tufa ; no trace of Spon- 

 giolites or Polygastric Infusoria, and nothing to indicate the vicinity 

 of the sea, but on the contrary many remains of Dicotyledonous plants 

 and grasses, and sporangia of lichens, reminding one of the consti- 

 tuents of the Moya of Pelileo. Whilst C. Saiute-Claire, Deville, and 

 George Bornemann, in their beautiful analyses of the Macalube di 

 Terrapilata, found 0.99 of carburetted hydrogen in the gas emitted, the 

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

 them, like Turbaco formerly, 0.98 of nitrogen, without a trace of. 

 oxygen (Comptes rendus de I'Acad. des Sciences, t. xliii, 1856, pp. 361 

 and 366). 



