Dr. Carl Ochsenhis — On Metalliferous Deposits. 313 



of the Utah Board of Trade for the year 1879 says, "The first 

 settlers there found sufficient soda for household purposes in the 

 Emigration Canon lying to the east of Salt Lake City;" but this 

 report is the only work in which the existence of carbonate of soda 

 in Utah is noted. CI. King adverts to this striking circumstance in 

 these words :^" It is a noticeable fact that in such a dense saline 

 solution (sc. the Great Salt Lake) one in which the solid matter is 

 approximately 15°/^ of the entire weight, there are none of the 

 alkaline carbonates which are characteristic elements in the saline 

 lakes farther west. In the absence of carbonates, Great Salt Lake 

 resembles the Dead Sea ; but in the enormous predominance of 

 chloride of sodium over all other salts, and in the entire absence of 

 carbonates, it is unlike any other large lake the analysis of whose 

 waters has been published." 



Now it is very clear that the continued presence of carbonate of 

 calcium in the water of the lake is impossible, because carbonate 

 of lime is precipitated from sea water of a specific gravity of 1*0506, 

 and the water of Great Salt Lake has such a specific gravity only 

 in the margins of the lake after winter rains, and in the mouths 

 of rivers or streams running into it and occupying limited spaces, 

 whereas the specific gravity of the general body of water is 1"107. 

 The carbonate of lime contained in the influx water never reaches 

 the main body of the Great Salt Lake water of comparatively great 

 specific gravity, because it has already been deposited in its passage 

 through the narrow marginal band of water of less density, and this 

 is fully confirmed by the description of tufaceous limestone found in 

 some places on the shore, which according to CI. King contains 

 opaque, dust-like particles in mechanical combination and organic 

 matter like the roots of water plants, as well as minute mollusks 

 enveloped in the mass. 



Such deposits occur of course during the whole year at the mouths 

 of the constantly flowing rivers Jordan, Weber, and Bear, but at 

 other parts of the shore only during the wet season, when the rain 

 water drains lime into the lake. Sea water (as is evidenced by 

 Usiglio's exhaustive experiments) deposits, as has already been 

 mentioned, carbonate of lime when of the specific gravity of 1-0506 ; 

 that is, as soon as its volume has been decreased to about half by 

 evaporation ; when the concentration is continued however, until the 

 water occupies i of its original volume, traces only of carbonate of 

 calcium are deposited ; but when the reduction goes on until the 

 water occupies only about 19°/o of its original volume (specific 

 gravity 1-1304), a second precipitation of carbonate of calcium 

 appears nearly as heavy as that which first occurred containing 0'0o3 

 as against 0-064: of the first deiDosit. This latter deposit occurs in 

 consequence of the interchange of components of carbonate of 

 sodium and sulphate of calcium forming sulphate of sodium and 

 carbonate of calcium. Gypsum and carbonate of soda remain un- 

 changed only in weak solutions. Usiglio has determined with great 

 exactitude the two periods of precipitation of carbonate of lime from 

 sea water. The concentration of the Great Salt Lake water is not 



