222 FOSSILS. 



irreligion; but we are firmly persuaded that our 

 views ought to have no such tendency ; we do not 

 call in question religion, but the right of allegorical 

 and ambiguous compositions to rank as truth, and 

 as guides in geological investigations ; but anxious 

 as we are for this, we are still more solicitous to be 

 thought the advocates of natural science, and of the 

 cause of truth, against ignorance, prejudice, and 

 error. 



Before concluding this paper, I wish to state the 

 results of some experiments, made with the view of 

 ascertaining the comparative difference between these 

 fossil bones and bones of ordinary occurrence. I 

 have before stated that they had a very dry ap- 

 pearance, and that they absorbed moisture with 

 rapidity. What then determines their absorbent 

 property ? In order to reply to this, I proceeded to 

 the experiment of freeing bone of its earthy portions, 

 by means of muriatic acid, being confident that the 

 proportion of matter thus obtained, would be such 

 as to furnish an explanation. I selected a piece 

 of fossil bone, from the Yealm Bridge Cave, 

 and another piece of the same weight from a 

 bone which had lain exposed in the high-road, 

 perhaps for many months. These I put macera- 

 ting in diluted muriatic acid, in separate glass 

 vessels ; as soon as the fossil bone was immersed, 

 violent and rapid action was observable, carbonic 

 acid gas being extricated in abundance ; gradual 

 corrosion, or ratlier a gradual removal of the earthy 

 portions, proceeded ; and, in the space of seven hours 

 it was reduced to a spongy, fiocculent mass, which, 

 having now become lighter than the fluid, rose to 

 the surface, putting on the appearance of a mere 

 pellicle. This having been collected ; weighed 

 eleven grains. In the other vessel, a quiet and de- 

 liberate escape of gas took place. In the space of 

 seven hours, the earthy portions had been removed 

 only to one half of the depth of the piece, and, after 

 the process was complete, it remained at the bottom, 



