420 APPENDIX F. — CHEMICAL ANALYSES. 



The water of tlie Hot Spring was found to have the specific 

 gravity of 1.0130, and one hundred parts yielded solid contents 

 1.1454. 



Chloride of sodium 0.8052 



Chloride of magnesium 0.0288 



Chloride of calcium 0.1096 



Sulphate of lime 0.0806 



Carbonate of lime 0.0180 



SiHca 0.0180 



1.0602 



Native Sal^ratus and Alum. 



The specimen labelled Efflorescence from a Salceratus Pond, on 

 the Sweetwater River, has been tested, and found to be composed 

 of the sesquicarbonate of soda, mixed with sulphate of soda and 

 chloride of sodium, and is one of the native salts called Trona, 

 found in the Natron Lakes in Hungary, Africa, and other countries. 



Three grammes of this salt in dry powder, cleared of its earthy 

 impui'ities, gave carbonic acid 0.9030 of a gramme, which would 

 indicate 1.73239 grammes of the sesquicarbonate. The other salts 

 were found to be the muriate and sulphate of soda: the proportions 

 were not determined. 



The specimen of alum from Alum Point, Great Salt Lahe, is a 

 rare and interesting mineral. It is a true alum ; but instead of 

 being an alum with an alkaline base, as potash or soda alum, it is 

 found to be an alum with a base of manganese, differing from all 

 other true alums in crystallizing in needle-shaped quadrilateral (?) 

 prisms. It is soluble in several times its weight of water. It has 

 the taste of ordinary alum, though less strong, from the fact, per- 

 haps, that it is less soluble. 



The mineral is an effloresced mass, found on the surface of a slate 

 rock abounding with a sulphuret (as is believed) of manganese, from 

 the decomposition of which the sulphur, being oxidized, is converted 

 into sulphuric acid, and combining directly with the base, manga- 

 nese and the alumina of the slate, forms the alum in question. 



The specimen, as it reached me, had lost nearly all of its water 

 of crystallization ; and, in order to make a fair analysis of it as a 

 specific salt, a portion of the specimen was dissolved in water and 

 recrystallized, and the crystals dried to the first appearance of 

 efflorescence on the projecting points, and then a given weight of 



