Phosphatic Materials used for Agricultural Purposes. 1 



it is found in several places in the Tyrol and Switzerland, also 

 in Bohemia, Saxony, Bavaria, Sweden, and Norway. Most 

 commonly it occurs in thin seams, imbedded in crystalline or 

 volcanic rocks, but seldom in sufficient quantity to repay the 

 cost of working. 



Mineralogists distinguish several varieties of apatite. Some 

 specimens are regular crystals, others crystalline, others foliated 

 or conchoidal. The colour varies as much as its crystalline 

 structure ; but, generally speaking, apatite has a light green or a 

 reddish colour. The apatite which at present is imported into 

 England from Norway is found chiefly at Krageroe. 



Two specimens of red-coloured apatite furnished, on analysis, 

 the following results : 



No. 1. No. 2. 



Hygroscopic water 43 -43 



Water of combination *40 '40 



'Phosphoric acid 41*88 41/74 



Lime 53-45 54-12 



fChloride of calcium .. 1-61 1-61 



Magnesia .. *20 



Phosphate of iron and alumina '66 *45 



insoluble siliceous matter 1-24 -97 



Alkalies .. -30 



99-67 100-22 



* Equal to tribasic phosphate of lime (bone-earth) 90*74 90'44 

 f Containing chlorine 1*03 1'03 



These specimens had a bright red colour like ironstone, and 

 yet they contained but very little oxide of iron. Two other 

 samples of very light green-coloured, almost white, apatite from 

 Krageroe, were found to contain : 



No. 1. No. 2. 



Hygroscopic water *19 '298 



Water of combination *23 -198 



'Phosphoric acid 41-25 42-28 



Lime 50'62 53'35 



fChloride of calcium 6-41 2-16 



Oxide of iron -29i Q9 



Alumina '38 f 



Potash -04 



Soda -13 



Insoluble siliceous matter *82 '99 



100-36 100-196 



* Equal to tribasic phosphate of lime (bone -earth) 89*37 91-60 

 t Containing chlorine 4'09 1'38 



It will be seen that these samples of Norwegian apatite con- 

 tain a very high percentage of phosphate of lime, only a small 

 amount of foreign impurities, and no carbonate of lime whatever. 

 They are also perfectly free from fluorine, which is present in 



