On the Danger of Hasty Generalization in Geology. 435 



was found, on which Mr Geikie lays so much stress, and is in- 

 deed the point oVappui of his whole argument. Instead of 

 finding this bed to be of marine origin and distinctly strati- 

 fied, as Mr Geikie has described it, we found it (as any one 

 can determine the fact for themselves) to consist of two dis- 

 tinct beds. The lower one, which rests on gravel, is evidently a 

 marsh silt due to the overflowing of the Water of Leith, the 

 remains of which may still be seen about 100 yards to the 

 west. That this marsh existed not in the Roman age, but 

 within the memory of the oldest inhabitant, is rendered highly 

 probable, by the situation bearing the name of Puddock Hall, 

 evidently from its proximity to the abode of frogs. That this 

 marsh silt was deposited long posterior to the Roman occupa- 

 tion, we shall endeavour in the sequel to prove. The silt 

 stratum or lower portion of bed (5) contains no remains of 

 animals nor pieces of pottery ; when dessicated by exposure to 

 the air, it separates into prisms perpendicular to the clay-bed 

 below, and is thus easily differentiated from the upper stratum 

 in which Mr Geikie found the so-called Roman pottery. 



The upper portion of No. 5 is distinguished from its lower 

 congener by numerous vesicular coal cinders, evidently acted 

 on by heat, and as the matrix shows no symptoms of fusion 

 from internal heat or otherwise, I take leave to denominate as 

 simply coal ashes. Side by side with the incinerated coals we 

 found oyster shells, not all lying flat, as deposited in a bed, but 

 at all angles to the horizon, precisely as any one may find 

 them in a humus bed, where a farmer, knowing their worth for 

 manure, had shot them in at random. Nor were the stones, 

 as Mr Geikie has said, lying on their sides (as would have 

 been the case if this bed had been a lacustrine or marine de- 

 posit) but were arranged in as higgledy-piggledy a manner 

 as the oyster shells. We, with the assistance of Mr Field's 

 men, had no difficulty in supplying ourselves with from 

 thirty to forty specimens of pottery, also bones of sheep, the 

 common ox(Bos taurus), teeth of the same, and also of the horse. 

 Only one evidence of the deer was found, and that was a tooth. 

 Before entering into the further proof of this bed being of 

 very modern origin, let us consider first the occurrence of the 

 burned coal so largely sprinkled through its mass, and ask 



