170 



The Scottish Naturalist. 



coloured body is obtained, which, on further analysis, is proved 

 to be chlorophyll, the substance which gives the green colour to 

 the leaves of plants. The presence of this chlorophyll goes far 

 to prove the vegetable origin of at least a part of the peat. On 

 the application of heat the peat chars, and loses 25*29 per cent, 

 of its weight. The microscopic examination of this organic 

 portion shows it to be made up of cellulose and ligneous matters 

 derived from vegetable sources. The remaining 65*55 P er cent, 

 after allowing for 7*45 per cent, of moisture, is made up of 

 inorganic material, principally composed of flinty silicious skele- 

 tons of diatoms. The material under the microscope presents a 

 most beautiful field, the diatoms being both numerous and vari- 

 ous, and interspersed with particles of silica and mineral matter of 

 undoubted metamorphic origin." 



The " While Peaty 



Moisture, 7*450 



Organic Matter, soluble in Ether (Chlorophyll, &c), ... 1708 

 Organic Matter insoluble in Ether (Cellulose, Lig- 



nose, &c. ), ... ... ... ... ... ... 25*290 



Inorganic Constituents, ... ... ... ... ... 65*552 



IOO'OOO 



An Analysis of the Inorganic Constituents shows the 



presence of Minerals, ... ... ... ... 17*040 



Silica 82*960 



1 00 "000 



It is noticeable from the analysis that these diatoms are simply 

 small flinty silicious fossils of the skeletons of some sort of vege- 

 tation, but so small that they can be observed only under a very 

 powerful microscope; a classification of some 200 species of them 

 has been made by the Rev. Dr. George Davidson of L.ogie- 

 Coldstone. 



Regarding the accumulation of such vast banks of this diatom- 

 aceous deposit, it is a little difficult to arrive at even a reasonable- 

 looking theory. Diatoms in a primitive state can be got from any 

 stagnant pool of water, and many curious specimens have been 

 dredged from a great depth in the sea. It is noticeable, however, 

 that the deposit in Loch Kinnord is situated on the west side of 

 the loch, and close to the base of a granite hill, from which a 



