88 



THE GEOLOGIST. 



What is its history r Bones of animals, we know, are formed of 

 phosphorus and lime (phosphate of lime), but not a trace, save 

 rarely a few teeth of sharks or tiny vei-tebree of fish, of bones of any 

 Kving thing of earth, or air, or sea is there — so far as we can see ; 

 and yet there ai-e tons and thousands of tons of what we only know 

 in an organic form as bone- substance. There are the gnarled riddled 

 boughs of trees, charred into radiate blackness in the lapse of incom- 

 prehensible time, and these are rich in, nay, permeated, soaked, so to 

 speak, with the phosphatic matter, for they offer to the chemist's test 

 as much per cent, as these hard, black-brownish lumps. There ai'e 

 broken phosphatic casts of the rough rugged Ammonites mammilaris 



Ligii. 12. — Ammo7iifes mammilaris. From the " Jiinction- (phosphate of Ume) bed." 



in numbers, bedaubed and patched with phosphatic concretions, but 

 nothing else, save of shell-fish a few stra}' straggling Inocerami or 

 Dontnlia, which only occasionally occm'. 



These phosphate-nodules, I should think, must have been derived 

 from some organic substance, the gi^eat accumulation of which at 

 one horizon, however, is very remarkable. Could the perishing car- 

 cases of gigantic Ammonites, such as the A. mammilaris in its adult 



