in the Strata of the Earth. 



523 



the appointed purveyors of future food for man, destined by 

 the functions of their daily digestion, and of their life and death 

 and decay, to lay up stores of universal fertility in the deep foun- 

 dations of the earth, and to prepare the nascent strata in the very 

 act of their construction, to become, in due time, a grateful soil 

 to reward the labours of the agriculturist.* 



As the processes we have been tracing in the London clay are 

 types of operations that have more or less pervaded all deposits 

 formed under water, in all formations, I will state further parti- 

 culars respecting this London clay. Phosphoric matter, elabo- 

 rated in the bodies of animals, has not only become combined 

 with the earthy ingredients of its larger septaria, the Roman 

 cement stones, but also with the millions of minor concretions 

 that crowd the London clay, and which often envelope fragments 

 of some animal or vegetable that formed a nucleus around which 

 the materials of these concretions were collated and aggregated 

 while in a fluid state. 



Many of these half-calcareous concretions in the London clay 

 contain enough of phosphoric matter to place them in the family 

 of pseudo-coprolites, the history of which, in other formations, I 

 shall presently describe ; we are now considering the fate and 

 fortune that has attended these minor phosphoriferous concre- 

 tions of the London clay. From their matrix in the London 

 clay they were dislodged by the waters of the seas of the eocene 

 period, and accumulated by myriads at the bottom of those shal- 

 low seas where is now the coast of Suffolk. Here they were long 

 rolled, together with the bones of large mammalia and fishes, 

 and with the shells of molluscous creatures that lived in shells. 

 From the bottom of this sea they have been raised to form the 

 dry lands along the shore of Suffolk, whence they are now ex- 

 tracted as articles of commercial value, and ground to powder in 

 the mills of Mr. Lawes, at Deptford, to supply our farmers with 

 a valuable substitute for guano, under the accepted name of copro- 

 lite manure. 



But it is not certain that these pseudo-coprolites collected all 

 their phosphates whilst they were in the London clay. It is possible 

 that many, if not all of them, and also many fragments of the larger 

 septaria, which we find rolled and broken in the crag, may have 

 absorbed a larger dose of phosphorus than they contained before 



* This self-same process, which has been made to lay up in every stratum, during 

 the act of its formation, stores of fertility for the then future lands and continents, pro- 

 duced a simultaneous reaction advantageous to the sanitary state and habitability of 

 the waters of the sea ; for had not this or some other process of purification been in 

 continual operation, from the time when living things of all dimensions, from the 

 infusorial animalcules to the sharks and great sea lizards and whales (Eualiosauri and 

 Ceteosaurij, were first created to inhabit the sea, the exuviae of these myriads (not- 

 withstanding diffusion) would, in a few centuries, have tainted all oceans and waters 

 with impurities exceeding those of which we hear so much complaint in the waters of 

 the Thames at London Bridge. 



