104 ECONOMICAL MINERALOGY. 



It is well known that the principal brine springs in tliis county cluster around the margin 

 of Onondaga lake, a fine sheet of water about six miles in length and one mile in width. The 

 water of this lake is not, as has been stated, salt at the bottom, but is fresh throughout.* The 

 salt water, found every where on the marsh which forms the boundary of the lake, is prevented 

 from communicating with the fresh water, by a bed of marl from three to twelve feet in thick- 

 ness, below which is a stratum of marly clay. 



There are at present on the marsh surrounding this lake, several wells and pump works for 

 the raising and distributing of brine, under the direction of the State authorities, at the villages 

 of Salina, Sjn:acuse and Geddes, and on the Oswego canal near the village of Liverpool. 



Salina Wells. There are three or four wells or shafts at the village of Salina, from which 

 brine is obtained. They are from seventy to seventy-five feet in depth ; and the brine is 

 raised by means of forcing pumps into reservoirs sufficiently high and capacious to supply the 

 works at this village, and tliey formerly also frequently supplied the works at Syracuse and 

 Liverpool. According to observations made in July, 1837, the pumps at Salina raised four 

 hundred and eighty-two gallons of brine in a minute, or twenty-eight thousand nine hundred 

 and twenty gallons in an hour. This amount, however, is supposed to have increased greatly 

 since the new shafts have been sunk. The present Superintendent, Mr. Spencer, states that 

 the three new shafts sunk in 1840 afford a large supply of excellent brine of a maximum 

 strength of 75°, which, however, is reduced during the summer to 65°. t 



The old Salina well was opened sixteen or seventeen years since. The brine from this I 

 have, carefully examined ; but its composition probably does not differ, except in the proportion 

 of the ingredients, from that which has recently been brought into use. 



The temperature of the Salina brine, during its passage from the pumps into the reservoir, 

 is 50° F., which is probably very near the temperature at its source. The brine is perfectly 

 limpid, and has a somewhat sparkling appearance, owing to the escape of a small quantity of 

 carbonic acid which it contains, and which holds in solution a minute portion of the carbonates 

 of lime and of iron. 



Nutgalls and ferro-cyanate of potash, when added to the brine recently drawn, exhibit the 

 changes of colour which are due to the presence of a salt of iron ; but they have not the least 

 efl!ect upon the brine after it has been exposed for a few hours to the air. Indeed, even when 

 kept in a well-corked bottle for eighteen hours, these tests produced scarcely any effect. This 

 is owing to the fact that the iron exists in the form of carbonate, and is held in solution by an 

 excess of carbonic acid, and in this state causes the changes of colour which are produced 

 when the proper tests are added ; but when this excess of carbonic acid escapes, as it does 

 by the expostire of the brine to the air, the oxide of iron falls down in reddish flocks, and the 

 tests then produce no effect. 



♦ In the paper on these springs, wliich I published in I8''.'ri, it, was stated that the water of Onondaga lake was salt at the bottom, 

 on the authority of Dr. B. De Witt. It now, however, appears, from repeated observations and experiments, that this is not the 

 case. 



t Report of the Superintendent and Inspector of Sail in Onondaga Counli/. January, 18-11. 



