24 ^^iouw City Academy of Science and Letters. 



magnet. Here is a specimen of "spiegeleisen" brought 

 from Prussia because of its richness in carbon. It is 

 extensively used in the manufacture of Bessemer steel. 

 All are familiar with the appearance of the metal mer 

 cury or quicksilver. Here is the ore from which it is 

 obtained. It is called Cinnabar, and came from Califor- 

 nia. From these most useful minerals to the more com- 

 mon ones we call rocks is only a step. Our collection 

 contains many varieties of these. Granite, sandstone, 

 limestone, diorite or hornblende are a few of the names 

 we know them by. All our building and paving stones 

 belong to this class of minerals. The volcanic rocks we 

 have in a fine lot of specimens, such as lava, obsidian or 

 volcanic glass, pumice, etc. From the Sandwich Islands 

 came this specimen, which looks like gray hair from 

 some animal. The natives called it Pele's hair from one 

 of their gods. It is blown out of the Volcano Kilauea, 

 on the island of Hawaii, and is a form of obsidian. 



From the wonderful petrified forest of Arizona we 

 have a large lot of specimens of the wood of long ago, 

 in their many beautiful shades of color, all changed to 

 stone. Many other specimens of petrified wood are here 

 from other localities. In another case are a large lot 

 of crystalized minerals, the most common of which are 

 quartz, or silica, and lime. All minerals are found at 

 times in these crystalized forms. From the Hot Springs 

 region of Arkansas, the Black Hills of Dakota and the 

 Yellowstone National Park they have come to us by the 

 hands of our friends. Here are beautiful clusters of 

 limpid quartz crystals, with other crystals of colored 

 silica, such as amethysts, smoky quartz and garnets. 

 Geodoes of quartz, rough on the outside but lined with 

 beautiful crystals. Then the many forms of lime crystals 

 in clusters, geodes and single ones are shown in our 

 cases. Gypsum or sulphate of lime from which our ce- 

 ment and plaster of paris are made is here both in crys- 

 tals and in massive form. Beautiful forms of chalcedony 

 we have in numbers. Large and fine specimens of mica 

 from the mines of North Carolina and our western states 

 is shown. Kock salt from Germany and Wyoming is 

 here. 



