1852.] LOGAN — POTSDAM SANDSTONE FOOT-PRINTS. 209 



Examinations of Phosphatic matters^ supposed Bones, and Coprolites, 

 occurring in the Lower Silurian Rocks of Canada. By T. S. Hunt, 

 Chemist to the Canadian Geological Survey. 



Supposed coprolite from Lac des Allumettes, in sandstone, with 

 Lingulce. — Porous, having a specific gravity of 2*875. By ignition 

 gave out water and an animal odour like burnt horn, and the vapours 

 temporarily browned turmeric paper. It dissolved in acids with 

 slight effervescence, leaving a residue of pure granular silica, which 

 was in grains distinctly visible on fracturing the mass. 100 parts 

 gave on analysis — 



Phosphate of lime (P05, 3CaO). . 36-38 



Carbonate of lime 5*00 



Maenesia . . 1 i i ^ no 



r\ • J c- > by loss 7'02 



Oxide 01 iron J "^ 



Insoluble siliceous grains 49'90 



Volatile 170 



10000 

 Another fragment gave 42*54 of siliceous matter. The brown matter 

 replacing or filling the Lingulce in the bed was found to be phosphate, 

 with a little carbonate of lime and animal matter, with siliceous par- 

 ticles. 



No. 2. Coprolite from Chazy limestone, Hawkesbury. — Yellowish 

 within, but penetrated for a little depth by a blackish matter (pro- 

 bably infiltrated oxide of iron) . The powder when heated in a tube 

 gives off so much ammonia as to produce white fumes with acetic 

 acid. 100 parts gave — 



Phosphate of lime 44*70 



Carbonate of lime 6*60 



Carbonate of magnesia 4*76 



Oxide of iron 8*60 



Insoluble siliceous matter .... 27*90 



Volatile matter (water in part) 5*00 



97-66 

 No. 3. Fragment of supposed cylindrical bone from Riviere Ouelle. 

 — It was blackish brown and compact. Within it was filled with 

 earthy matter (the imbedding sandstone), which was not entirely 

 detached before the analysis. Its analysis gave, for 100 parts, as 

 follows : — 



Phosphate of lime 67*53 



TVT '•' > as carbonates and fluorids < , ^^ 

 Magnesia] \ 1"d5 



Oxide of iron 2*95 



Insoluble (in part, the adherent matrix) 21*10 



Volatile 2*15 



97-82 



