PEALE.] CHEMISTRY OF DEPOSITS SILICEOUS SINTEE, ETC. 407 



original deposit of one of the springs. The analyses of the waters have 

 already been considered, and we now take up the deposits, beginning 

 with Viandite. 



VIANDITE (Groldsmitli n. 8.). 



Before giving Mr. Goldsmith's remarks and analysis I will refer briefly 

 to its mode of occurrence. Its appearance is described by Mr. Gold- 

 smith as seen in the specimens that are still moist. When dried it 

 resembles somewhat leather, although it is more brittle. It is found 

 in sheets surrounding some of the springs where the surface is flat 

 enough to aUow the water to stand and become cool. In other places 

 it occurs in long waving fibers, or in sponge-like forms. It is rusty- 

 brown, reddish, or pink, and even greenish, and sometimes pure white. 



A glance through the chapters in Part I of this report will show that 

 it is found in the Geyser Basins of the Fire Hole in the Shoshone Basin, 

 and on the shores of the Yellowstone Lake, as well as in the Grand 

 Caiiou of Yellowstone. The specimen described and analyzed by Mr. 

 Goldsmith is from the Shoshone Geyser Basin, where it was taken from 

 the mound of deposit on which the south group is located. 



Most writers, in speaking of this curious deposit, are inclined to con- 

 sider it a vegetable growth, and compare it to mycelium or the mother 

 of vinegar. 



VIANDITE, A NEW VAIUETT OP SILICA. 

 By E. Goldsmith. 



A specimen of a very peculiar lookiug material was collected by Dr. A. C. Peale in 

 the Shoshone Geyser Basin, Yellowstone National Park, on the 25th of August, 1878. 

 Dr. Hayden forwarded it to Professor Joseph Leidy, who transferred it to me for in- 

 vestigation. The material had been packed in a small tin bos, and, although not her- 

 metically sealed, may have been preserved in such a state as it was originally found. 

 The soft moist substance has not the appearance of a mineral ; it looks like a partly 

 decomposed meat with bits of fat intermingled. The color is partly brown and gray, 

 with patches of white irregularly distributed. It is so soft that it may be easily 

 compressed with the fingers, by which process some water is separated. After such 

 pressing it remains flat, showing, therefore, no elasticity. The odor is somewhat 

 foul, but not strong. I determined the specific gravity with 1.729 grams of substance 

 and found it to be 1.120. 



When 10 grams of the material were exposed on steam during sixteen hours, there 

 remained but 2.457 grams; hence 24.57 per cent, of dry substance, and 75.43 per cent, 

 of loss, which is nothing else but water. 



The dried substance is softer than talc, and is porous. It crumbles easily between 

 the fingers to fine i)Owder. The color of the powder is straw-yellow. It is tasteless 

 and has no odor. Specific gravity was found with 0.4S3 gram of the substance to be 

 =l.:U2. 



When pieces of the dry substance are thrown on water they remain floating on the 

 Bin face until they absorb some of the water, when they will sink, but they seem to 

 poH.«ess a certain buoyancy, 



Bloupijjc reactions. — When heated in a closed tube it affords a dense gray cloud which 

 condenses partly into Avater and partly to an oily matter. In thin layers the oil is 

 yellow, in thicker, dark brown. The odor of the fumes are penetrating strong, tary ; 

 the straw-yeilow powder became black. When heated on platinum foil it changes to 

 black first, which quickly disappears, leaving a white powder. Heated on charcoal, it 

 showed no sign of fusion. Fused with sodium corbonate, it forms a glassy slag with a 

 faint bluish coloration, indicating a trace of manganese. With solution of cobalt there 

 ie also i)i'oduced a pale-blue coloration. lu microcosmic salt it is but partially soluble ; 

 the beail is slightly pinkish in both the oxidizing and the reducing flame. 



Hydrochloric acid, as well as sulphuric acid, do not dissolve the substance. In 

 order to bring it into solution it was fused with carbonate of soda and treated as a 

 silicate. 



Under these circumstances I recognized the following oxides : silica, alumina, iron, 

 lime, traces of magnesia, and manganese. 



Qiiantitatire anabiHix. — 1.100 grains of the steam-dry substance lost, on ignition, 

 0.1(i4 grams^= 14.91 per cent, of organic matter, with i)robaljly some water. After 



