98 PROCEEDINGS OF THE ACADEMY OF [1898. 



THE PETRIFACTION OF FOSSIL BONES. 

 BY E. GOLDSMITH. 



The Port Kennedy limestone quarry, situated on the Schuylkill 

 River, in Montgomery Co., Pa., became noted some twenty-five years 

 ago for a deposit of fossil bones which were studied, in part, by Pro- 

 fessors Joseph Leidy and Edw. D. Cope. Recently a fresh interest 

 in the subject was awakened, and Mr. Mercer, the well-known archae- 

 ologist, superintended some further diggings, especially in the hope 

 of finding human remains in the fissure, the receptacle of the fossils, 

 in the Silurian limestone. 



Mr. Mercer's statement that a considerable part of those fossil 

 bones crumbled, or, as he expressed it, " fell to a mealy powder" 

 when touched, attracted my attention. In order to ascertain into 

 what form and composition the bone-phosphate had been changed, 

 I visited the locality and saw the peculiar position of the fissure 

 filled with the moist debris derived from the overlying Mesozoicred 

 sandstone. The mealy matter above referred to was easily found 

 because there was more of it than solid fossil bones; although it is 

 astonishing how many fragments of bones were in view, a sight de- 

 lightful to the paleontologist. 



I selected for my investigation a curved bone, apparently a trans- 

 verse section of a scapula of perhaps one of the larger cats, about f 

 of an inch thick in the middle and tapering toward both ends. 

 Clean material could easily be dug out with a knife. On drying 

 the sample it appears as a yellowish, fine sand of even grain : Mr. 

 Mercer's fossil bone meal. This fine grained mealy material was 

 certainly at one time, a portion of a bone ; but its composition is no 

 longer calcium phosphate, a chemical analysis proving that phos- 

 phoric acid was almost or entirely absent. The reaction for phos- 

 phoric acid with the ammonium molybdate solution was very slight, 

 there seemed to be but a small fraction of one per cent, of the cal- 

 cium phosphate left in the specimen. It was further ascertained 

 that this so-called bone-meal is now essentially calcium carbonate 

 containing some magnesia. Is this material really amorphous as it 

 appears under ordinary conditions? A slide, prepared in the ordi- 



