Science, Geology and Physics 



shape, and others in clumps of acute six-sided crystals, both 1809 

 having a resemblance to the dogs-tooth-spar. All these are 

 probably modifications of the calcareous carbonate, by admix- 

 tures of magnesia, silex, and perhaps some other ingredients. 



These layers of limestone are interspersed with small masses 

 or lumps of gypsum. This is generally of a snowy whiteness, 

 and indeterminate figure. But it is mistaken by some people for 

 the petrified froth of the river. It seems to be formed in con- 

 sequence of the decomposition of the pyrites imbedded in some 

 parts of the rock. The sulphuric acid to which this process gives 

 rise, expels the carbonic acid, and unites with the limestone by 

 virtue of a more powerful attraction. Thus the common lime- 

 stone is converted into plaster of paris; or in chymical language, 

 the carbonate of lime is changed into a sulphate. The two com- 

 pounds very commonly exist together, the limestone and gypsum 

 cohering and making parts of one mineral mass. In some rills 

 where the brimstone appears not to have been combined with 

 oxygen, it oozes out with the water, and discolors the rocks. 

 Thus native sulphur and calcareous sulphurets, may be enume- 

 rated among the natural products of Niagara. 



To enable the kind and quality of the calcareous rocks, in 

 the western territory of New- York, and the adjacent parts of 

 Canada, to be understood, it ought to be mentioned that organic 

 remains, apparently of animals, are frequently found in them, 

 the greater part of the way from the Seneca Lake to Niagara 

 River, a distance of a hundred miles. At the remarkable sul- 

 phureous spring in the town of Phelps, eleven miles northwest 

 of Geneva, they appear like corralines and madrepores. On both 

 sides of the Genesee and Ionewanto rivers, they resemble marine 

 shells. While on the east and west banks of Niagara river, they 

 assume, in addition to the already enumerated forms, those that 

 have erroneously been called petrified wasp's-nests and honey- 

 combs. In some cases these calcareous petrifactions are blended 

 with pyrites ; and in others they are impregnated with a petroleum 

 or bituminous matter, called Seneca oil. These petrifactions do 



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