1913-] STEVENSON— FORMATION OF COAL BEDS. 159 



fragmentary; a great part of the tissues was transformed into a 

 vegetable pulp, which makes up most of certain coal beds. Long 

 ago Lesquereux described mature peat in very similar terms, the 

 fragmentary materials being embedded in an amorphous material, 

 consisting of organic acids and their salts. Von Giimbel's descrip- 

 tion is much the same ; the amorphous material, much of which was 

 originally flocculent, is his Carbonhumin, which binds together the 

 plant fragments and the often abundant mineral charcoal, which he 

 terms, Torffaserkohle. The cementing material, soluble in the bog, 

 becomes insoluble on drying. Grand-Eury's description of coal 

 applies equally to matured peat, especially well to that of the Ameri- 

 can cypress swamps. It is thoroughly applicable to the " coal balls " 

 as well as to the Grand'Croix flints, all of which are regarded by 

 investigators as petrified peat. 



In one respect, however, the description does not apply to many 

 peat deposits. Coal often consists largely of flattened stems, the 

 interior having disappeared. On preceding pages, the presence of 

 prostrate stems and erect stumps has been mentioned as characteristic 

 of old or new Waldmoors in all parts of the world. According to 

 Harper, such stems and stumps are so abundant in many Florida 

 swamps as to make the peat commercially worthless ; Cook says that 

 in the New Jersey swamps stems of white cedar are so numerous 

 that one has difficulty in thrusting a sounding rod through the mass. 

 Similar crowding of stems appears to be a familiar feature in the 

 deposits of northern Europe, according to all observers from De Luc 

 to the present. In very large part, the wood is fairly well preserved ; 

 the Irish bog oak and the New Jersey white cedar are utilized by 

 cabinet-makers. Grand'Eury's description afifords the explanation. 

 There was little woody material in most of the Carboniferous trees ; 

 there is much in the conifers and oaks of modern swamps. But 

 woods of other types do occur in flattened condition within peat; 

 von Giimbel found them at the depth of only one meter, so that the 

 collapse w^as not due to pressure. Friih made the same observation 

 in the great Digenmoor of the Bavarian highland ; the late-Quatern- 

 ary Schieferkohle contains flattened stems of harder woods — and 

 here too the deformation is not due to pressure, for cones, not de- 



