262 J. W. Dawson on Spore-cases in Coals. 



with coal. Dr. Hunt says—" The outer bark of the Cork tree 

 and the cuticle of many if not all other plants consists of a 

 highly carbonaceous matter, to which the name of svherin has 

 been given. The spores of Lycopodium also approach to this 

 substance in composition, as will be seen by the following, one 

 of two analyses by Duconi,* along with which I give the theo- 

 retical composition of pure cellulose or woody fiber, according 

 to Payen and Mitscherlich, and an analysis of the suberin of 

 Cork, from Quercus suber, from which the ash and 2-5 per cent 

 of cellulose have been deducted, f 



Cellulose. Cork. Lycopodium. 



Carbon, 44-44 65-73 64-80 



Hydrogen, 6-17 8-33 8-TS 



iNitrogen, 1-50 6-18 



Oxygen, 49-39 24-44 20-29 



100-00 100-00 100-00 



This difference is not less striking when we reduce the above 

 centesimal analyses to correspond with the formula of cellulose. 

 Ca^HggOgd and represent Cork and Lycopodium as contain- 

 ing 24 equivalents of carbon. For comparison I give the com- 

 position of specimens of Peat, Brown Coal, Lignite, and Bitu- 

 minous Coal.:!: 



Cellulose, C24 H20 O20 



Cork, C24 Hi8t^^ OetV 



Lycopodium, Czi HioA ^^'^ 



Peat, (Vaux), C34 HmtV <^io 



Brown Coal, (Schrother), C24 IlMfV O^oA 



Lignite, (Vaux), C24 HiiA OeA 



Bituminous Coal, (Regnault), C24 Hio Ogx^ir 



It will be seen from this comparison that, in ultimate compo- 

 sition, Cork and Lycopodium are nearer to Lignite than to 

 woody fiber ; and may be converted into coal with far less loss 

 of carbon and hydrogen than the latter. They in fact approacU 

 closer in composition to resins and fats than to wood, and more- 

 over like those substances repel water, with which they are not 

 easily moistened, and thus are able to resist those ^ atmospheric 

 influences which effect the decay of woody tissue." 



I would add to this only one further consideration, i'^^ 

 nitrogen present in the Lvcopodium spores no doubt belong 

 to the protoplasm containe"d in them, a substance which won 

 soon perish by decay ; and subtracting this, the cell-walls ot tu 

 spores and the walls of the spore-cases would be most s^}"^"' 

 material for the production of bituminous coal. But this sui 

 ableness they share with the epidermal tissue of the scales 

 ♦ Liebig and Kopp, Jahresbuch, 1847-48. f Gmelin, Handbook, iv, 1^ • 



; Canadian I^faturalist, vi, 253. 



