VOL. LXXXIV.] PHILOSOPHICAL TRANSACTIONS. 445 



one having some tenacity, but the other like wet dust; but in some of the harder 

 bones it is more firm. 



In the fossil bones of land animals, and those which inhabit the waters, as the 

 sea-horse, otter, crocodile, and turtle, the animal part is in considerable quantity. 

 In the stags' horns dug up in Great Britain and Ireland, when the earth is dis- 

 solved, the animal part is in considerable quantity, and very firm. The same ob- 

 servations apply to the fossil bones of the elephant found in England, Siberia, 

 and other parts of the globe; also those of the ox kind; but more particularly to 

 their teeth, especially those from the lakes in America, in which the animal part 

 has suffered very little; the inhabitants find little difference in the ivory of such 

 tusks from the recent, but its having a yellow stain ; the cold may probably as- 

 sist in their preservation. The state of preservation will vary according to the 

 substance in which they have been preserved; in peat and clay I think the most; 

 however, there appears in general a species of dissolution; for the animal sub- 

 stance, though tolerably firm, in a heat a little above 100° becomes a thickish 

 mucus, like dissolved gum, while a portion from the external surface is reduced 

 to the state of wet dust. 



In incrusted bones, the quantity of animal substance is very different in dif- 

 ferent bones. In those from Gibraltar there is very little; it in part retains its 

 tenacity, and is transparent, but the superficial part dissolves into mucus. Those 

 from Dalmatia give similar results when examined in this way. Those from 

 Germany, especially the harder bones and teeth, seem to contain all the animal 

 substance natural to them, they differ however among themselves in this respect. 

 The bones of land animals have their calcareous earth united with the phosphoric 

 acid instead of the aerial, and I believe retain it when fossilized, nearly in pro- 

 portion to the quantity of animal matter they contain. 



The mode by which I judge of this, is by the quantity of effervescence; when 

 fossil bones are put into the muriatic acid it is not nearly so great as when a shell 

 is put into it, but it is more in some, though not in all, than when a recent 

 bone is treated in this way, and this I think diminishes in proportion to the quan- 

 tity of animal substance they retain; as a proof of this, those fossil bones which 

 contain a small portion of animal matter, produce in an acid the greatest effer- 

 vescence when the surface is acted on, and very little when the centre is affected 

 by it; however, this may be accounted for by the parts which have lost their 

 phosphoric acid, and acquired the aerial, being easiest of solution in the marine 

 acid, and therefore dissolved first, and the aerial acid let loose. In some bones 

 of the whale the effervescence is very great; in the Dalmatia and Gibraltar bones 

 it is less; and in those the subject of the present paper it is very little, since they 

 contain by much the largest proportion of animal substance. 



