PREFACE. 
IX 
numerous figures which are here given, from cuts prepared by Mr. Peckham of 
New-York, will sufficiently attest the richness of our localities in this respect. 
To render this part of the work convenient for reference, all the figures scattered 
through the volume have been collected in the form of tables, with the mea¬ 
surements of the several angles. I should state, that in regard to the projections 
of crystalline forms, Brooke’s “ Introduction to Crystallography,” and Haiiy’s 
“Traite de Mineralogie,” have been my principal guides. In the measurements 
of angles, however, I have often adopted the views of Phillips, and other more 
recent authors, in preference to those of Haiiy, for reasons which will be under¬ 
stood by the mineralogist. 
As there is some difference in this respect, it may be proper to state, that the 
scale of hardness which I have followed is that proposed by Mohs, and which is 
as follows, viz: I, Talc; 2, Gypsum; 3, Calcareous spar; 4, Fluor spar; 5, 
Apatite ; 6, Adularia ; 7, Rock crystal; 8, Topaz ; 9, Corundum ; 10, Diamond. 
The history of the progress of Mineralogy in the State of New-York, is in 
some measure connected with that of Geology. The former science, however, 
was cultivated here long before geology assumed the form of a distinct and im¬ 
portant branch of knowledge. 
Attention was turned to the study of mineralogy in this State about the end 
of the last century. It is to the late Dr. Samuel L. Mitchill, of New-York, that 
the science is indebted for the first movement made in its behalf. The first and 
second volumes of the Medical Repository, published in 1798 and ’99, contain 
“ A Sketch of the Mineralogical History of the State of New-York,” by that 
gentleman, which, although meagre in its details, shows that even at that early 
day the business of collecting materials upon this subject was commenced. In 
1799, a Mineralogical Society was formed in the city of New-York, the first in 
the United States. The circular address of that society was published in the 
second volume of the Medical Repository. Dr. Mitchill was the president of 
this association; and, as he himself states, its object was to “ arm every hand 
