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IV. — -Some Observations on the Chemical Composition and Agri- 

 cultural Value of the Fossil Bones and Pseudo-Coprolites of the 

 Crag. By Thornton J. Herapath. 



It was not many years since that the celebrated Professor Liebig:, 

 of Giessen, in one of his works on agricultural chemistry, observed, 

 when writing on the importance of phosphate of lime in the vege- 

 table economy, ^' In the remains of an extinct animal world, Eng- 

 land is to find the means of increasing her wealth in agricultural pro- 

 duce, as she has already found the great support of her manu- 

 facturing industry in fossil fuel." At that time, however, little 

 or no attention was paid to the prediction, which was regarded 

 merely as one of the few brilliant but erroneous speculations that 

 have emanated from the master-mind of the same most eminent 

 philosopher ; but more recently, guided by science, geologists and 

 agriculturists have succeeded in demonstrating its truth, and have 

 shown that, in many of the formations which constitute (if I 

 may be allowed to use the expression) the groundwork of this 

 island, lie concealed mines of manure almost equal in value to 

 the guano of Africa and Peru, which is now oftentimes collected 

 with so much risk and labour, and eagerly purchased by our far- 

 mers at so high a price — a manure, indeed, which only requires to 

 be subjected to certain simiple treatment in order to become a 

 rival of that most remarkably fertilising substance in alleviating 

 the w^ants of the ag^riculturists. The existence of these fossil re- 

 mams in our son was, I believe, first pointed out by Drs. Man- 

 teil and Buckland, though it is to Professor Henslow that we 

 are indebted for having called attention to their eminent agricul- 

 tural value, and described the localities whence they may be most 

 readily obtained. 



Phosphoric deposits have been met with in several formations ; 

 but would seem to occur in by far the greatest abundance in the 

 more recent tertiary strata, as a layer between the coralline crag 

 and London clay. The layer or stratum in question varies in 

 thickness in different localities, sometimes averaging not more 

 than two inches, whereas at others it often exceeds a foot or 18 

 inches in thickness. It consists almost entirely of the fractured 

 and rolled bones of cetaceous and other animals, which have been 

 thrown up and deposited there in the convulsion that ended the 

 clay deposit and ushered in the crag or deeper sea formation. 



Mixed with these bones are found many fish-teeth and shells 

 of different species, and likewise immense numbers of rolled 

 water-worn pebbles, which, at one period, were imagined to be the 

 fossilized excrements of the animals themselves, and were on this 

 account called coprolites by Professor Henslow and others. Re- 

 cently, however, the fallacy of this view has been proved, and Pro- 



