38 Dr Grant ow n Fossil Tooth found in Red Sandstone 



are not easily obtained with accuracy, but there is little difficulty 

 in tiacing any change of the deviation produced by the Aurora 

 with the requisite precision. A needle, suspended by a fibre of 

 silk in a glass case, and playing against a scale of equal parts, 

 will answer the purpose in default of a more complete apparatus. 

 It should, however, be frequently examined, for (as has been 

 stated) it often indicates the existence of Auroras not otherwise 

 perceptible. 



ON A FOSSIL TOOTH FOUND IN A RED SANDSTONE ABOVE THE 



COAL FORMATION IN BERWICKSHIRE. In a JLtiter fvom Dr 

 B, JS. Grant, 



My Dear Sir, 

 I RETURN you the interesting specimen of the Fossil Tooth 

 in the Red Sandstone * you had the kindness to submit to my 

 examination, and I am greatly obliged to you for the opportu- 

 nity you have afibrded me of forming my own opinion about a 

 specimen, which is likely to be the subject of some controversy 

 and speculation, in consequence of the judgment respecting it, 

 pronounced by a most skilful and indefatigable anatomist, who 

 has deteimincd it to be the tooth of a wolf. As I am )equested 

 to state my opinion respecting the tooth, and as my examination 

 of it has led me to a different conclusion from that of my able 

 friend Mr Cliff, I feel called upon to justify that opinion, by 

 stating the reasons that have led me to it. The white colour, 

 the glistening surface, the conical and curved form, and the 

 smoothness of the tooth, it is true, give it much the appearance 

 of the canine tooth of a carnivorous quadruped, and its size and 

 length I find to correspond nearly with that of the upper jaw of 

 a wolf. But notwithstanding this general resemblance, on a 

 closer examination the comparison entirely fails ; the tooth of the 

 wolf is pi oportionably thicker and more curved, and is less com- 

 pressed, particularly in its cavity for the pulp. The tooth of the 

 wolf, and of other carnivorous quadrupeds, is covered on its 

 crown with a thick layer of enamel, which resists the knife like 



• This 13 the Fossil Tooth mentioned in our former Number, as having 

 been found by General Lord Greenock, and which we considered as belong- 

 ing to a fossil species offish. — Edit. 



