THE GEOLOGIST. 
AUGUST 1862. 
M. GRAS' ATTACK ON THE EVIDENCE OF THE FLINT- 
IMPLEMENTS IN EESPECT TO THE ANTIQUITY 
OF MAN. 
It is extraordinary how many people have an obliquity in their 
mental vision. Some mentally never see straight at all, but look at 
everything askew. These are harmless people ; you know them at 
once, and pity their defects, just as you do a person with a downright 
squint. But those who have a slight cast in the eye are the most 
dangerous ; you are not aware they occasionally squint ; you do not 
perceive, perhaps after even a close scrutiny, that there is anything 
amiss with their vision at all. So it is with the mental cast ; you do 
not observe it, as a general rule, for it is only now and then it shows 
itself. 
When the Antiquity of Man was first proclaimed from the dis- 
covery of the Abbeville flints by Boucher de Perthes, no one believed 
it. Everybody thought him like the mad man who swore all the 
world was mad ; and so it seemed, then, as if all the world had 
mental obliquity of vision, which made them declare our savant of 
Abbeville to be labouring under a delusion. When, however, Eigollet, 
Prestwich, Flower, Lyell, Evans, and others of the goodly company 
of geologists, — as unbelieving, however, as so many St. Thomases, — • 
went, saw, and returned believing, the fame of Boucher de Perthes' 
discoveries gained ground. Some there were who hardened them- 
selves in their unbelief, and hazarded wild theories of ocean-waves 
chipping out artificial forms, and of recent objects sinking down in 
VOL. V. 2 o 
