254 



On American Phosphate of Lime. 



shire, in white limestone, on the land of Mr. Thomas Cross. In 

 Maine, on Long Island, Blue-hili Bay, in veins ten inches wide, 

 intersecting granite. In Massachusetts, crystals occasionally 

 six inches long are obtained at Norwich (north-west part), in 

 grey quartz ; at Bolton, abundant, the forms seldom interesting ; 

 also sparingly at Chesterfield, Chester, Sturbridge, Hinsdale, 

 and Williamsburgh. In Pennsylvania, at Leiperville, Delaware 

 county ; in Bucks county, three miles west of Attleboro. Apatite, 

 or mineral phosphate of lime, has also been found near Balti- 

 more, Maryland ; at Dixon's Quarry, Wilmington, Delaware, of 

 a rich blue colour; on the Morris Canal near Suckasunny, New 

 Jersey, of a brown colour, in massive magnetic pyrites ; also at 

 Perth, Canada. 



(2) External Characters. 

 Hexagonally crystalline ; also globular or kidney-shaped, with a fibrous 

 or imperfectly columnar structure, and massive, with a granular structure. 

 Lustre vitreous, inclining to subresinous. Streak, white. Colour usually 

 sea-green, bluish-green, or violet-blue ; sometimes white ; also occasion- 

 ally yellow, grey, red, and brown ; none bright. Transparent — opaque. 

 A bluish opalescence sometimes in the direction of the vertical axis, 

 especially in white varieties. Cross fracture conchoidal and uneven^ 

 Brittle. It is about 3J times heavier than water. 



(3) Chemical Composition. 

 According to Professor Rose, apatite is composed of — 



Phosphate of lime (or bone-earth) . . . 92'3 



Fluoride of calcium (or Derbyshire spar) . . 7'7 



100- 



The following analyses represent the composition of 100 parts of speci- 

 mens from Norway, Spain, and the Tyrol, respectively : — 





From 

 Snarum 

 in 



Norway. 



From Cabo 

 di Gata, in 

 Spain. 



From 

 Arendal in 

 Norway. 



From 

 Greiner 

 in 



the Tyrol. 



From St. 

 Gothard, 

 in 



the Tyrol. 



Phosphate of Lime . , 

 Chloride of Calcium 

 Fluoride of Calcium 



91-13 

 4-28 



4-59 



92-066 

 0-885 

 7-049 



92-189 

 0-801 

 7-010 



92*16 

 0'15 

 7-69 



92-31 

 a trace. 

 7-69 





100-00 



100 "000 



100-000 



100-00 



100-00 



Rammelsberg makes the composition of 100 parts of an apatite 

 from Schwarzenstein in Zillerthal : — Lime, 49*66; phosphoric 

 acid, 42 • 58 ; with calcium, 4 ' 06 ; chlorine, 0 • 07 ; fluorine, 3 • 63. 

 In a phosphorite from Estremadura, Dr. Daubeny found 14 per 

 cent, of fluoride of calcium. Mineral phosphate of lime is in- 

 fusible when heated alone by means of the blow-pipe ; but melts 

 without difficulty into a glass of crystalline structure on cooling, 

 when mixed with bi-phosphate of soda or with common borax : 

 it also fuses when mixed with carbonate of iron. In nitric acid 



