MODERN METHODS OF EXCAVATING, I'KKIWU 

 ING AND MOUNTING FOSSIL SKELETONS 



The work of collecting and preparing fossil bones is so 

 well known in the museums of America that it is not my 

 intention to explain in detail how to take up bones in the 

 field and to prepare them in the laboratory. Some of the 

 most modern methods adopted in the American Museum 

 of Natural History may, however, be of interest. 



Field Work 



Too much emphasis can hardly be laid upon the proper 

 treatment of bones in the field, because very crumbly but 

 precious specimens may be saved by proper treatment, 

 while, on the other hand, good specimens may be ruined 

 by wrong treatment. 



Up to recent years collectors in the field have used 

 almost exclusively gum arabic for saturating soft bones 

 in order to harden them, and while practical for very por- 

 ous bones it does not penetrate sufficiently into less por- 

 ous ones, so that they become hardened on the outside 

 only, remaining crumbly inside. Another disadvantage 

 is that gum will absorb moisture and loses its binding 

 properties in damp weather. Shellac will penetrate the 

 bones much more thoroughly than gum, and when suffi- 

 ciently dry will leave them much harder and absolutely 

 waterproof. For the last three or four seasons our col- 

 lectors have used a solution of shellac in place of gum 

 arabic with very good results; and this can be recom- 

 mended for any field work wherever the fossils are porous 

 and badly preserved. Brown shellac is better as it dis- 

 solves more easily and it is stronger, and should be used 



