PROOFS OF TRANQUIL ACTION 219 



that washed them have long since disappeared, can 

 still be followed for mile after mile across the 

 mountains and glens of the North- West Highlands. 

 So tranquil were these waters that their gentle currents 

 and oscillations sufficed to ripple the sandy floor, to 

 arrange the sediment in laminae of current-bedding, 

 and to separate the grains of sand according to their 

 relative densities. We may even now trace the results 

 of these operations in thin darker layers and streaks 

 of magnetic iron, zircon, and other heavy minerals, 

 which have been sorted out from the lighter quartz- 

 grains, as layers of iron-sand may be seen sifted 

 together by the tide along the upper margins of 

 many of our sandy beaches at the present day. 



In the same ancient formation there occur also 

 various intercalations of fine muddy sediment, so 

 regular in their thin alternations, and so like those 

 of younger formations, that we cannot but hope and 

 expect that they may eventually yield remains of 

 organisms which, if found, would be the earliest traces 

 of life in Europe. 



It is thus abundantly manifest that even in the 

 most ancient of the sedimentary registers of the earth's 

 history, not only is there no evidence of colossal 

 floods, tides and denudation, but there is incontro- 

 vertible proof of continuous orderly deposition, such 

 as may be witnessed to-day in any quarter of the 

 globe. The same tale, with endless additional details, 

 is told all through the stratified formations, down to 

 those which are in the course of accumulation at the 

 present day. 



Not less important than the stratigraphical is the 



