402 Dr. Thomson's A?ialt/sis of Needlestone. [Dec. 



ties were discovered in the mine of Adelfors, in Smoland, some 

 of which did not accm-ately agree with Cronstedt's description, 

 though they were all confounded together under the general 

 appeUation of zeoUle. And many fine crystallized specimens 

 -were brought from the Ferro Islands, and distributed through 

 the different mineral cabinets of Europe. Werner, when he 

 translated Cronstedt's system into German, satisfied himself 

 with subdividing the species zeolite into subspecies. These were 

 gradually increased in number ; and in Hoffman's Handbuch der 

 Mineralogie, published at Freyberg in 1811, 1812, 1815, 1816, 

 1817, and 1818, which exhibits the Wernerian system of minera- 

 logy in its latest and most perfect form, zeohte (purporting to 

 include the mesolype and stilbite of Haliy) is subdivided as 

 follows : 



First subspecies mealy zeolite, 



Second subspecies fibrous zeohte, 



first kind .... common, 

 second kind. . needle zeolite. 



Third subspecies radiated zeolite. 



Fourth subspecies foliated zeolite. 



Besides these, Werner introduces into his system as separate 

 species, cithizite, shabasite, lomoiiite, natroUte, and one or two 

 others which had been at first confounded under the name 

 zeolite. 



In the year 1796, M. Haliy published in the fourteenth num- 

 ber of the Journal des Mines (p. 86), a short paper entitled 

 *' Observations sur les Zeohthes." In this paper he subdivides 

 zeolites into four distinct species, distinguished by the shape of 

 the crystals of each. These were mesotypc, stilbite, aualcime, 

 and chabasite. 



Mesotypc is the zeolite of Cronstedt. Its primitive form, 

 according to Haliy, is a rectangular prism with square bases. 

 The ratio between a side of the base and the length of the prism 

 is v' 5 : 2. The specific gravity of mesotype is 2-0833. It 

 becomes electric by heat, like the tourmalin, the summits of the 

 crystals being plus, and the part where they were attached to 

 the matrix minus. It gelatinizes in acids, froths when heated, 

 and melts into a spongy enamel. 



Stilbite is the radiated and fohated zeolite of Werner. Its 

 primitive form is a rectangular prism with a rectangular base. 

 The breadth, heighth, and length, of this prism are to each othcj, 



as the numbers -J^, \^ 3, 3 \/ 2. It does not become electric by 

 heat, nor does it gelatinize in acids. Its specific gravity is 2'5. 



It is unnecessary to give Haliy's characters of analcime and 

 chabasite, as they are universally admitted to be distinct species, 

 and have nothing to do with our pi^sent subject. 



NatroUte was named and described by Klaproth in 1803. It 

 occurs either amorphous, or in crystals as fine as hairs, the form 



