368 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1954 



ment and the isolated molar tooth are of recent or modern age. The 

 foregoing conclusions are supported by evidence concerning the or- 

 ganic content of the specimens, as determined by analysis of their 

 nitrogen content. This method is not as conclusive as fluorine analy- 

 sis; but its results, given in the third column of the accompanying 

 table, provide additional support for the conclusions arrived at by 

 the fluorine-estimation method. In general, as would be expected, 

 the nitrogen content decreases with age ; the only specimen that falls 

 out of line is the occipital of Piltdown II. 



Table 1. — Fluorine content, ratio of fluorine to phosphorus penioocide, and nitrogen 

 content of the bones and teeth of the so-called Piltdown I and Piltdown II skulls, 

 compared with those of various Upper Pleistocene and Recent bones and teeth. 

 (From Weiner, Oakley, and Clark [1], rearranged.) 



%FX100 

 /" % P2O5 ^^^ 



Upper Pleistocene: 



Bones (local) (minimum F content) 0. 1 0. 4 



Teeth, dentine (minimum F content) 0. 1 0. 4 



Bone (London) 0. 7 



Equine molar, dentine (Piltdown) 1.2 



Human molar, dentine (Surrey) 0. 3 



Recent: 



Neolithic bone (Kent) 1.9 



Fresh bone 4.1 



Chimpanzee molar, dentine <0. 06 <0. 3 3. 2 



Piltdown I: 



Cranium 0.1 0.8 1.4 



Mandible, bone <0. 03 <0. 2 3.9 



Mandibular molar, dentine <0. 04 <0. 2 4.3 



Canine <0. 03 <0. 2 5.1 



Piltdown IT: 



Frontal bone 0.1 0.8 1.1 



Occipital bone 0.03 0.2 0.6 



Isolated molar, dentine <0. 01 <0. 1 4. 2 



Weiner, Oakley, and Clark also discovered that the mandible and 

 canine tooth of Piltdown I and the occipital bone and molar tooth 

 of Piltdown II had been artificially stained to match the naturally 

 colored Piltdown I cranium and Piltdown II frontal. Whereas these 

 latter cranial bones are all deeply stained, the dark color of the faked 

 pieces is quit« superficial. The artificial color is due to chromate and 

 iron. This aspect of the hoax is complicated by the fact that, as re- 

 corded by Smith Woodward [21], "the colour of the pieces which 

 were first discovered was altered a little by Mr. Dawson when he 

 dipped them in a solution of bichromate of potash in the mistaken idea 

 that this would harden them." The details of the staining, which 

 confirm the conclusions arrived at by microscopy, fluorine analysis, 

 and nitrogen estimation, need not be entered into here. 



