1825.] Specimensof the Soil uf the Cavern of Kuhloch. 295 



alcohol produced a brisk effervescence when treated with weak 

 hot muriatic acid. The solution was filtered when cold, and 

 the matter remaining upon the filter was washed with water 

 until nitrate of silver showed that it contained no muriatic acid ; 

 the filtered liquor resembled muriate of platina in colour. The 

 washings which contained a notable excess of acid were slightly- 

 coloured ; while the latter which contained none were of a deep 

 colour, which proves, that the colouring organic matter when 

 uncombined, is more soluble in pure water, than in that which is 

 acidulated. 



39. The muriatic solution upon the addition of a little water 

 deposited a red crystalline matter, resembling that ofdeutoxide 

 of manganese ; the solution was filtered, and the red powder 

 washed. 



When subjected to distillation, this red powder yielded an 

 acid water, and afterwards oily ammonia ; a sulphurous product, 

 and afterwards a quantity of charcoal which left only a trace of 

 non-effervescing ferruginous ash, probably containing alumina. 

 This powder, when heated in the air, burnt, giving out sparks 

 like the charcoal which is set on fire by nitro-sulphuric acid. 



The filtered muriatic solution was mixed with muriate of 

 barytes ; there was no sensible precipitation in 24 hours; never- 

 theless I filtered the liquor twice, and evaporated it to dryness. 

 The residuum when distilled gave a sulphurated product ; and 

 when it was calcined with nitrate of barytes, and the whole again 

 treated with nitric acid, sulphate of barytes was obtained. The soil 

 of Kiihloch, therefore, contains some sulphur which is not in the 

 state of sulphuric acid. Is it in that of an hyposulphate, or of 

 sulphuretted hydrogen combined with organic matter? oris it in 

 combination with organic matter without beins; in the state of an 

 acid? These are points which I cannot decide. 



40. The matter undissolved by muriatic acid (38) was treated 

 with boiling alcohol, and the solution filtered. 



41. This solution did not contain any sensible quantity of 

 fatty matter, for the residue of evaporation was totally soluble in 

 cold water. This residue when distilled yielded an acid water, 

 a trace of sulphurated product, a thick brown matter, some sub- 

 carbonate of ammonia and charcoal. 



42. The residue undissolved by alcohol (40) consisted of 

 silica, alumina, magnesia, peroxide of iron, a trace of oxide of 

 manganese,* yellow colouring matter, some alcoholic extract 



• Having burnt this residuum, I obtained a cinder, which was partly dissolved by 

 nitric acid without effervescence. The solution was precijjitated by ammonia, and the 

 precipitate consisted of alumina and peroxide of iron. The filtered solution was of a 

 purplish rose colour, resembling that of the suljihate of lime obtained from the specimen 

 A (I'iJ) ; at first I attributed this colour to manganese ; to determine this I evaporated 

 the solution to dryness, and obtained a black powder mixed with nitrate of magnesia ; the 

 latter dissolved in water, but the former did not. 'I'hc black powder contained iron and 

 a trace of manganese, but the small quantity of cameleon obtained by heating the powder 

 in potash, induced me to think that there was another matter which escaped mc. 



