[Senatk 



CARBURETTED HYDROGEN* 

 (Mineralogy of New- York, pages 128 and 172.) 



The Avork as above quoted, contains a full account of the occurrence- 

 of this gas in various parts of the State. Subsequent researches have 

 shed very little further light upon the question of its origin. We have 

 indeed the negative evidence that in the western part of the State, 

 where its evolution is most abundant, it does not arise from the decom- 

 position of coal; and Mr. Hall asserts that "the amount of organic 

 matter, both animal and vegetable, known in this rock, (Medina sand- 

 stone) is so exceedingly small, that it could scarcely be supposed to 

 give rise to the constant emission of this gas. The impervious nature 

 of the lower part of the mass, and the absence of fossils in the next 

 rock below, would preclude the idea of its origin in that direction, as 

 there are no disturbances known in the district." Report of the Geology 

 of the Fourth Geological District^ p. 44. 



One of these gas springs is noticed by Prof. Mather, as occurring at 

 Haverstraw, in Rockland county. Report on the Geology of the First 

 District, p. 107. 



ORDER n. NON-COMBUSTIBLE GASES. 



NITROGEN* 



(Mineralogy of New-York, pages 133 and 174.) 



Mr. Hall remarks, " that there is scarcely a doubt but the Canoga 

 springs have their origin along a line of fault or fracture in the strata. 

 Those of Chateaugay, in Franklin county, are near the junction of the 

 granite and Potsdam sandstone, and in the calciferous sandrock." Report 

 mi the Geology of the Fourth District, p. 309. 



CARBONIC ACID'. 

 (Mineralogy of New- York, page 175.) 



ACIDULOUS, OB CARBONATED SPRINGS. 



Congress Spring, Saratoga. In the appendix to Fownes' Chemistry, 

 1845, Phila. edition, I find a table of the anhydrous ingredients in one 

 pound Troy of the water of this spring, by Dr. Schweitzer. The num- 

 ber of substances there given is much larger than that heretofore de- 

 tected in these waters by other chemists. Among these are, carbonate 

 of strontia, protocarbonate of manganese, sulphate of potassa, nitirate- 



