Notes on the Society's Work in 1897-1918. lxxvii. 



Lignite. 

 Schomburgk during his journey in the thirties of the last century 

 down the Corentyne Kiver thought he had discovered the existence of 

 carboniferous stata in Guiana. Recent investigations have proved that 

 the fragments of coal he saw were not lignitic but are the eggs deposited 

 there as a mare's nest years prior to his visit. They consist of 

 pieces of water-worn bituminous coal. Pieces of bituminous coal, not 

 infrequently water-worn can be found along the banks of the lower 

 courses of several of our rivers, as for instance the Essequibo ; and in places 

 on the seashore and elsewhere. This condition also exists on the lower 

 reaches of some of the rivers in the neighbouring colony of Surinam. 

 These derelicts were thrown from the holds of ships, whilst loading timber, 

 which had brought coal to Guiana. It is, however, not to these carboni- 

 ferous mares' nests I am at present alluding, but to the fact that deposits 

 of lignite are now known to exist on the Demerara River Doubtless there 

 are others in the colouy. With modern methods for making " Producer- 

 gas " it is probable that such deposits may become of some importance in 

 our industrial pursuits. 



Mares' Nests. 



Mares' nests are of somewhat common occurrence in the low-lands 

 and along the foot-hills of the Guianas. Mineral eggs, with which many 

 of them have been charged, have been frequently brought tome forexami- 

 natien during the period under review. Pieces of refinery and of 

 bloomery or puddlers' slags, bv-products of former processes for the man- 

 ufacture of wrought-iron which doubtless arrived here as ships' ballast, 

 have been brought to me doing duty as meteorites or as ores of some 

 rare but unknown metal ; blocks of coral limestone ; pieces of Belgian 

 black marble ; fragments of black-lead pots (plumbago cruciblesj ; pellets 

 of lead of solder and of tin ; small bits of antimony ; quicksilver in small 

 quantities ; black and yellow spelters ; lumps of pitch or asphaltum; water- 

 worn, rounded pieces of pot-glass ; chalk flints ; and especially masses of 

 lateritic bauxite have been among the numerous eggs I have had submit- 

 ted to me. The wide areas over which these reliquae occur are remarkable. 



Our Dutch predecessors not infrequently used bauxite, especially the 

 harder ferruginous bauxites, for making the foundations of their buildings 

 as it was the readiest available hard-stuff on the lower reaches of the 

 rivers. Aboriginal Indians are responsible for many geological mares' 

 nests either by their former practice of bringing shell-fish such as oysters 

 in quantities to special places for their feasts (there is a mare's nest of 

 ostrea-shells covering nearly an acre and in places several inches in 

 thickness and situated about 2 feet from the surface near the 

 base of the Issorora Hill, N. W. District) or by carrying large pieces 

 of rock from one place to another to use as anchoring-stones for 

 their corials. I mention these as in this colony every prospector and 

 geologist must be constantly on his guard against the contents of such 

 mares' nests. 



