GEOLOGICAL KEPOKT. 285 



not to mention the gypsum, which effloresces from many of the rocks. In Captain 

 Stansbury's report these salt-ponds have been mentioned, and the incrustation of one 

 of them, near Independence Rock, is stated there to be composed of about 58 per 

 cent, of sesquicarbonate of soda, besides sulphate of soda and muriate of soda, which 

 is the composition of the salt called "trona," also found in the natron-lakes of Hun- 

 gary, Africa, &c. 



I took several specimens of such salts in that neighborhood, and have subjected 

 them to a few tests before the blow-pipe. One of them is mainly sulphate of soda, 

 free of carbonic acid and chlorine; another one contains in addition a little carbonate 

 of soda and probably also of magnesia, but no chloride; and a third one sulphate of 

 soda, with a large percentage of carbonate of soda, and some little chloride of sodium, 

 and is similar to the trona mentioned above, although from a different locality. 



These salt-ponds, with their concentrated brine, cause the death of large numbers 

 of cattle, which prefer to drink this water because it is salt, and because they always 

 like more to drink from standing pools than from swiftly-running streams. The effect 

 is not sudden, but after the poison has staid some time in the body death follows after 

 a few hours of sickness. The strong and fat are affected as well as the weak and lean. 

 Citric acid and vinegar are said to be antidotes, and we can well account for their ben- 

 eficial influence; a dose of oil or bacon may likewise be successfully administered. 



Coal — We have seen that coal abounds along Platte River. It is inferior to the 

 stone-coal of the Carboniferous formation, but partly, at least, it is a superior brown 

 coal and a very valuable fuel. In its appearance it is similar to stone-coal, of black 

 color, and mostly great luster, while others present a dull black surface. The streak 

 and powder are dark brown, which is also the color of weathered pieces. When fresh 

 it splits into cuboid fragments, but after being exposed for some time to the atmos- 

 phere it becomes laminated. I have not made any tests of the Deer Creek coal, but 

 on a former occasion I have analyzed a coal of the same formation from the Upper 

 Platte River, which closely resembles it (see Lieutenant Bryan's report of 1856), and 

 found in it, by distillation, with slowly increased heat— 



45.5 per cent, of fixed carbon ; 

 5.0 per cent, of ashes, partly gypsum ; 



49:5 per cent, of volatile substance and water. 



The coal which I. have examined was obtained near the outcrop, and, therefore, 

 not quite fresh. In the interior of the stratum it may be more bituminous. It burned 

 with a long flame, retained its shape in coking, and did not cake at all ; on the con- 

 trary it split in every direction. The coke was hard and brittle, dark gray, with a 

 metallic luster ; it would not withstand much pressure, nor well endure transportation 

 without much loss by slacking. The heating power of such coal is less than that of 

 the stone-coal of the Carboniferous formation, and in weak traveling forges this coal 

 from the outcrops frequently does not afford a good welding heat, but with arrange- 

 ments specially adapted to it, it can be made to produce the highest heat required in 

 the manufacture of iron. For high furnaces the coke would probably not have suf- 

 ficient cohesion. It would seem to be less fit for locomotives than for stationary ma- 

 chines, on account of the large grate-surface which it requires ; but this obstacle could 

 certainly be overcome. 



