46 NEW YORK STATE MUSEUM 



admit. They are all serpentine, more or less impure, and of various 

 shades of bottle green, black, gray etc. They all produce sulphate 

 of magnesia by oil of vitriol. These serpentines are at least new 

 varieties for our country. Some have a peculiar appearance like 

 bronze, owing to the small goldlike particles, with a lamellar struc- 

 ture, resembling bronzite or diallage metalloid. Also other particles 

 highly translucent, like precious serpentine, with frequently small 

 nuclei resembling devitrifications or porcelanites, colored white, yel- 

 low, blood red, variegated etc. The grain of this kind is like com- 

 mon serpentine. In other kinds, the mass seems to be made of 

 small globuliform concretions, varying in size, being centers of 

 aggregation ; some are of dark vitreous and serpentine, others of 

 the compact kind, the enveloping part of a light color. The first 

 impression of this rock is like some of the New Jersey trap rocks, 

 where amphibole is in imperfect crystals, or like pyroxenic lava, 

 with its imperfect crystals embedded in the more compact material. 



" These two principal varieties produce endless mixtures upon the 

 small scale, to say nothing of those derived from the difference of 

 shades of color, the presence of veins and mixtures with the asso- 

 ciated shales." 



" These serpentines seem to resemble the ophiolites of Tuscany 

 and Florence, and should the views of Brocchi be correct, they 

 must not only be similar in origin but in age." 



Vanuxem in his final report in 1842 (2) again describes this rock 

 under metamorphic rock and says : " The great interest of all these 

 metamorphic products is that they have not been caused by a dry 

 heat or fire, no evidence of the kind existing; nor is any needed to 

 effect the change there observed, though it can, and has, and does 

 produce the same results. All that is required, is the presence of the 

 elements of the products observed at Syracuse, and in a state admit- 

 ting of solution and of moisture, to which every degree of heat 

 added, would greatly aid their mutual action upon each other; and 

 from solution crystallization would take place, and thus metamorphic 

 products or rocks would be formed, no igneous action commonly 

 so-called being requisite, but a thermal one only." 



In the same year as Vanuxem's final report, 1842, Lewis C. Beck 

 in his Mineralogy of New York refers to this dike under the caption 

 Serpentine and quotes from Vanuxem's report. 



In 1858 Dr T. Sterry Hunt (History of Ophiolites (4)) says: 

 "At Syracuse, the strata between the two beds of porous limestone 

 just described, are much altered; the shales are rendered harder, 





