6 



THE GEOLOGIST. 



elude in my abstract. When the boilers of steam-ships are being 

 cleaned, procure portions of the calcareous deposits scaled off the 

 interior, and by treating them in the usual way with nitro-muriatic 

 acid, D iatomacean-f orms and Polycystina-sheUs may be detected in 

 considerable quantity. 



By obtaining these deposits from ships plying within known limits, 

 a series of free floating Diatomacece might be secured which would 

 afford good data for the ascertainment of their range, distribution, 

 and limits. And so, heartily thanking Dr. Wallich for this crumb 

 of friendly feeling, I close his pamphlet. The year that has just 

 departed has thrown no light of equal importance on geological history ; 

 though it has been a very notable year in geological science — 

 notable in the importance of its discoveries, thoughtfully made, and 

 carefully introduced ; and beyond measure notable in its crop of 

 theories, and in the agitations produced by them. But of these latter 

 " helps to knowledge" we have surely had enough. Dr. "Wallich has 

 sent the ball rolling in another direction ; and his labours are more 

 clearly reflected in the mirror of Truth than is any attempt to claim 

 creative power for the working of secondary principles. 



A CHRISTMAS LECTURE ON "COAL" 

 By J. W. Salter, E.G.S. 



Not a great many years ago the " bigwigs" in England were 

 assembled in conclave, and the elite of science was called before them. 

 There were a great many lumps of a blackish-brown substance on the 

 table, and a great deal of smelling, and burning, and poking of the 

 same black lumps by the same "bigwigs" and learned men. It was 

 the great " Torbane Hill Coal" case. 



" The point was in question, as all the world knows, 

 To what the said substances ought to belong." 



Was it pure carbon ? Was it carbonaceous shale ? Was it shale 

 without much carbon? Was it carbon without much shale? Was 

 it bituminous shale ? Was it coal-shale ? Was it cannel ? Was it coal ? 



We are afraid to say how many guineas were spent, or how many 

 microscopes were busy in London and Edinburgh. But after all 



