Phosphatic Materials used for Agricultural Purposes. 9 



of sheet-iron, it becomes beautifully phosphorescent hence its 

 name. 



In Estramadura this phosphorite has been employed as a 

 building-stone. Professor Hausmann, of Gottingen, in his classical 

 Handbook of Mineralogy, published in 1847, says with respect 

 to the Spanish phosphorite, that building purposes are probably 

 the only use to which this mineral can be applied. 



We in England of course know how to turn phosphorite to a 

 better purpose than that of building houses with it. The fact, 

 however, that such a valuable mineral is, or, more correctly 

 speaking, has been, used for building purposes not many years 

 ago, shows plainly in what immense layers it is to be found at 

 Lagrosa. It is to be regretted that the want of adequate means 

 of transport and other difficulties have hitherto prevented this 

 valuable deposit from being brought in large quantities to the 

 English market. 



Several large cargoes of Estramadura phosphate, it is true, 

 found their way hither two years ago, but the importers lost 

 money by the speculation, although the mineral was sold at a 

 rate quite high enough in comparison with the then current price 

 of bone-ash and other phosphates. 



The following analyses were made from average samples, 

 fairly representing the composition of the different cargoes : 



Composition of Spanish (Estramadura) Phosphorite. 



No. 1. No. 2. 



Moisture and water of combination '68 1*42 



Lime 42-68 41-47 



*Phosphoric acid 36'36 53-55 



Oxide of iron, alumina, magnesia, and] determined \ Q Q1 K.I a 



fluorine I by difference / 



Insoluble siliceous matter 11-47 18*37 



100-00 100-00 

 * Equal to tribasic phosphate of lime (bone-earth) .. 78'79 72-69 



It will be seen that the Spanish phosphorite is not equal to 

 the best samples of Norwegian apatite. It is, however, a valuable 

 mineral, since it is rich in phosphate and free from carbonate 

 of lime. 



Like Norwegian apatite, the Estramadura phosphorite must 

 be reduced by means of powerful machinery to a fine powder, 

 and afterwards treated with sulphuric acid, before it can be 

 economically employed for manuring purposes. 



Fibrous phosphorite has also been found at Amberg, in 

 Bavaria. This phosphorite resembles, in composition and struc- 

 ture, that of Estramadura, but is distinguished from it by con- 

 taining some iodine. 



Bavarian phosphorite has lately been raised in some quantities, 



