CHEMICAL SCIENCE. 229 



fectly clear and colorless. Organic matter dissolved in oil of vitriol 

 was separated from it by a thickness of stratum of only four inches. 

 A bottle of porter was by the same process deprived of nearly -all its 

 color. The material of which this filter is made is of little impor- 

 tance. One of the best, so far as clearing the water is concerned, is 

 composed of steel filings, oxide of iron, oxide of manganese, and pow- 

 dered bricks, all answering equally well. This shows that the sepa- 

 ration of the organic matter is due to some peculiar attraction of the 

 surfaces of the porous mass presented to the fluid. London Chemist, 

 October. 



LOWER BLUE LICK SPRINGS OF KENTUCKY. 



THE water of the Lower Blue Lick Springs has an extensive repu- 

 tation in Kentucky, and in the South generally, this being one of the 

 oldest and best-known watering-places in the valley of the Ohio and 

 Mississippi. This remarkable spring attracted the attention of the 

 earliest settlers of Kentucky, by its strong odor of sulphuretted hydro- 

 gen and the saltness of its waters. It was, indeed, from this source 

 that Boone and other pioneers obtained the salt with which to flavor 

 their venison. Anterior to the advent of the whites, this place was 

 the favorite resort of immense herds of buffaloes and other wild ani- 

 mals, who, led by instinct from different parts of the continent to drink 

 the saline waters, left as memorials of their presence extensive roads 

 or trails through woods and cane-brakes, which are visible even at 

 the present day. The geological formation in which these springs 

 occur is the same as that which underlies Cincinnati and the central 

 fertile region of Kentucky, called by Western geologists the great 

 blue-limestone formation, and constituting a lower member of the Si- 

 lurian system. This formation in some places is of great thickness, 

 composed of limestone layers of greater or less hardness and purity, 

 with beds of bluish marly clay, all exceedingly rich in fossils. The 

 well-known Big Bone Lick of Kentucky is seated on this same rock 

 formation, and the composition of the water of the spring in that 

 locality appears to be nearly analogous to that of the Blue Licks ; it 

 being a saline sulphur spring like the latter. Indeed, the blue lime- 

 stone is very generally known as a saliferous formation, which is 

 doubtless to be referred to its submarine origin. Numerous springs 

 of salt water have been found on it, and many salt wells, some con- 

 taining sulphuretted hydrogen, have been obtained in it by boring. 

 Associated with the water thus obtained by boring in the blue lime- 

 stone is sometimes found a large quantity of light carburetted hydro- 

 gen. The origin of this gas in the coal formations is doubtless from 

 the vegetable matter that formed the coal, but in this formation it is a 

 puzzleto geologists. Unless we suppose it to be derived, like the 

 fluid bitumen sometimes discovered in this formation, from the decom- 

 position of animal remains in the strata, no probable cause can be 

 given for its production. The temperature of the Blue Lick Springs 

 is about 62, or a little greater than the mean annual temperature of 

 the adjoining country. 



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