364 D. C DAVIES ON THE PHOSPHOKITE 



carbonate. The great preponderance of phosphatic organisms, with 

 which the period covered by the deposit commenced, gradually ab- 

 sorbed and secreted all carbonate of lime, whether held in solution 

 in the water or redissolved from the shells of dead mollusks ; and so, 

 turning it into phosphate, grew and multiplied exceedingly, and 

 became at last almost sole masters of the position by this appro- 

 priation, until the supply of carbonate of lime became insufficient for 

 their sustenance as the mineral conditions came on under which the 

 overlying shales were deposited. 



The more difficult question may be asked, What became of the 

 phosphatic matter of the animals of the myriad shells that compose 

 the fossiliferous layers in the Bala Limestone below the phosphorite 

 bed ? I would simply offer a twofold general answer to this inquiry : 

 first, perhaps the mechanical condition of the seas was unfavourable 

 to its quiet deposition ; and, secondly, perhaps owing to its diffusion 

 in the water, it was taken up by rapidly increasing succeeding gene- 

 rations of organisms, until, the sea- conditions becoming favourable, 

 it was finally deposited on the sea-bottom as the deposit we have 

 been considering. 



The comparatively low percentage of phosphatic matter in the 

 deposit, together with the cost of carriage to a railway, renders an 

 economic working necessary. I think, however, that it is now 

 proved that the deposit may be worked profitably. It is to be hoped 

 also that with the introduction of tramways into the Welsh valleys, 

 other portions of the deposit may be reached which are now practi- 

 cally inaccessible. Especially is this to be desired when we con- 

 sider that we have thus in North Wales many millions of tons of 

 fertilizing matter. The phosphorite is sent to chemical works as 

 free as it can be made of extraneous matter. It is there treated with 

 acids, which separate the phosphate of lime from the rest of the 

 mass. This is then ready to be used in the composition of a variety 

 of chemical manures. 



In concluding this paper I may perhaps be allowed one reflection, 

 which is this. To whichever side of geological inquiry we turn, we 

 see the life of ages long since gone by ministering to the life of to- 

 day. The world is ever being built of, and upon, the wrecks of past 

 creations ; and in the use made of the deposit we have been con- 

 sidering we have another illustration of the same truth. The low 

 organisms of a Cambro-Silurian sea contribute the force of the nerve 

 and the brain by which we are able to unravel the mysteries of 

 distant cycles of time, to grasp the distant future, and to comprehend, 

 to some extent at least, the wondrous economy of the universe. 



Analyses of North Wales Phosphorite. 



1. Cwmgwynen. General analysis given by Dr. Voelcker at the 

 meeting of the British Association in Birmingham in the year 1864. 



1st sample gave 64-16 of phosphate of lime. 

 2nd „ gave 48-50 „ 



