APATITE 201 



two pieces to be welded to a proper heat' by itself; and several men are employed in 

 working them together briskly in the welding state, by heavy swing hammers. The 

 stcci facing is applied by welding in the same manner. The anvil is then hardened, 

 by heating it to a cherry red, and plunging it into cold water a running stream being 

 preferable to a pool or cistern. The facing should not be too thick a plate ; for, when 

 such, it is apt to crack in the hardening. The face of the anvil is now smoothed 

 upon a grindstone, and finally polished with emery and crocus, for all delicate pur- 

 poses of art. 



The blacksmith, in general, sets his anvil loosely upon a wooden block, and in pre- 

 ference, on the root of an oak tree. The cutlers and file-makers fasten their anvils 

 to a large block of stone, their peculiar work rendering it an advantage to have the 

 anvil fixed as firmly and solidly as possible. 



The whitesmith, or brightsmith, when working at the anvil, unless the piece tinder 

 the hammer should be very light, is assisted by a striker, who wields a sledge-hammer. 

 In forging round articles, such as bolts, axles, &c., the smith makes use of swages 

 pieces of steel formed somewhat like hammer-heads with a groove in one corre- 

 sponding with a hollow in the other. In forging small spindles, the boss, or lower 

 piece, is permanently fixed upon the anvil. For convenience in managing heavy 

 articles, a crane is so fixed in the workshops, that the arm traverses between the fire 

 and the anvil. 



APATITE, (birardco to deceive}. A name proposed by "Werner, in 1786, for the 

 native crystallised phosphate of lime of Saxony, and since extended to all minerals of 

 like chemical composition. The name is suggestive of the deceptive appearances 

 which the mineral often presents, and which naturally enough led the early minera- 

 logists into the error of mistaking many of its varieties for widely-different sub- 

 stances. As apatite, when occurring in sufficient quantity to be advantageously 

 worked, has always a high economic value, it is desirable to describe the species 

 somewhat in detail. 



Apatite crystallises in forms belonging to the hexagonal system, frequently in 

 short six-sided prisms, each terminated either by a pyramid of as many faces, or by 

 a simple flat plane. The horizontal edges at the ends of the crystal are often variously 

 modified, and the lateral faces of the prism frequently exhibit vertical atrise. Clea- 

 vage is generally not well marked. In colour the mineral varies from white to various 

 shades of green and blue, passing sometimes into violet and brown ; but the ' streak,' 

 readily seen on scratching the mineral, is invariably white. The lustre is generally 

 glassy, but rather inclined to resinous. Some varieties of the mineral are trans- 

 parent, while others are qxiite opaque : it is notable that a bluish opalescence may 

 occasionally be detected in the direction of the vertical axis of the crystal. For a 

 salt of lime, apatite is rather hard, readily scratching glass, but being itself scratched 

 by felspar. Its specific gravity varies from 2-92 to 3'25. In chemical composition 

 all apatite consists mainly of phosphate of lime (calcium phosphate), but it was 

 shown by Eose in 1827 that this phosphate is almost invariably associated to a 

 greater or less extent with either chloride or fluoride of calcium, or with both. The 

 general composition of apatite maybe thus formulated: 3 (3CaO,P0 5 ) + Ca(Cl,F) ; 

 [3 (Ca 3 P 2 O 8 )-f Ca(Cl 2 , F 2 )]. The amount of phosphoric acid (phosphoric anhy- 

 dride) in apatite usually varies from 40 to 45 per cent. Heated before the blowpipe, 

 the mineral fuses, with difficulty, on the edges. Many massive varieties emit a phos- 

 phorescent glow when heated, and are hence termed phosphorite. 



Among the minerals commonly found in association with apatite, may bo specially 

 mentioned tin-stone, topaz, and tourmaline. It is with such associates that apatite 

 occurs in veins in St. Michael's Mount, and in several Cornish tin-mines ; and it is 

 also found under similar conditions in the tin-deposits on both the Saxon and the 

 Bohemian sides of the Erzgebirge, especially at Ehrenfriedersdorf, Zinnwald, and 

 Schlaggenwald. A variety in small white crystals, with curved faces, and in crystal- 

 line masses, occurring at Huel Franco and Fowey Consols, in Cornwall, has been 

 termed Francolitc. Near Bovey Tracey, in Devonshire, apatite was formerly found 

 in largo white crystals, associated with fine specimens of black tourmaline. At 

 Carrock Fells, in Cumberland, it occurs in green crystals, with smoky quartz, molyb- 

 denite and gilbcrtite. The dark greenish-blue crystals found in Norway and else- 

 where have been termed Moroxite. Snarum, in Norway, yields largo white crystals, 

 apparently decomposed. A crystalline apatite, flesh-red in colour, and looking much 

 like a felspar, is found at Krageroe in Norway, where it has been largely worked for 

 export to England. The variety termed by Werner Spargclstcin (' asparagus stone ') 

 occurs in beautifully formed clear yellowish-green crystals, associated with specular 

 iron-ore, in a peculiar rock, apparently volcanic, at Jumilla, in the province of Murcia, 

 Spain. A proposal was lately made to work the rock containing these crystals. At 

 Logrossan, in the province of Estrerandura, there arc vast deposits of massive or con 



