ON SO-CALLED GOLD-COATED TEETH IN SHEEP. 33 



On SO-CALLED GOLD-COATED TEETH in SHEEP. 



By A. LlVERSIDGB, LL.D., F.R.S., 



Professor of Chemistry, University of Sydney. 



[Read before the Royal Society of N. 8. Wales, June 7, 1905.'] 



Paragraphs have appeared recently in the newspapers 

 stating that gold coated teeth have been found in sheep ; 

 and within the last week I received the lower half of a 

 sheep's jaw bone from Mr. Charles G. Alford, the teeth of 

 which are more or less completely incrusted with a yellow 

 metallic looking substance, but more like iron pyrites 

 (marcassite) or brass than gold. The incrustation is brittle 

 and readily comes off in scales when even lightly scratched 

 with the point of a penknife. 



The surface of the tooth under the scale was found to be 

 black, but apparentfy not decayed, for when the black 

 coating is scraped off, the surface of the tooth is white ; 

 the thickness of the deposit does not apparently exceed the 

 ih of an inch, or less than 1 mm. Only one tooth was 

 scaled so as to destroy the specimen as little as possible. 

 The scale partly dissolves in dilute acid. The residue con- 

 sists of filmy organic matter, still possessing a metallic 

 sheen although white in colour instead of yellow. When 

 heated on platinum foil the scale blackens, partly fuses and 

 leaves a white residue soluble in dilute hydrochloric and 

 nitric acids. The residue contains phosphoric acid and 

 apparently consists mainly of calcium phosphate. Under 

 the microscope the scale is seen to be translucent and of 

 a pale brownish colour, and under a half-inch objective it 

 is seen to be made of thin layers, but there is no recognis- 

 able organic structure. The metallic lustre is clue to the 

 way in which the light is reflected from the surfaces of 



C— June. 7, 1905. 



