No. 275.] 
21 
the other from the Split Rock quarry, in Onondaga county. The fol- 
lowing are the results: No. 1 is from the former, — No. 2 from the 
latter. 
1. 2. 
Insoluble matters, consisting of silica and alumina, . 0.90 0.40 
Oxide of iron, 0.35 0.20 
Carbonate of lime, . . 98.50 99.30 
99.75 99.90 
29. Wayne and Niagara counties also contain marbles of excellent 
quality, both for ornamental and ordinary purposes. The Lockport 
marble contains fragments of organic remains, which give to its surface, 
when polished, a variegated and beautiful appearance. It also frequently 
presents on fracture that singular columnar structure, at right angles to 
the layers, which has been quite aptly compared by Mr. Vanuxem to 
the sutures of the skull. In consequence of a suggestion made by that 
gentleman that the appearance in question was owing to sulphate of 
magnesia,* I subjected a specimen to analysis, and was somewhat sur- 
prised to find in it a large proportion of that earth. The composition 
is as follows: 
Silica and alumina, 2.25 
Oxide of iron, 0.35 
Carbonate of lime, 75.65 
Carbonate of magnesia, 20 . 70 
Moisture and loss j 1 . 05 
100.00 
It wnll be interesting to ascertain whether this composition prevails in 
the rocks of this series. 
30. In the northern part of the State the localities of marble are no 
less numerous and important than in the southern and western parts. 
Thus, in Washington county, there is a fine clouded variety near Gran- 
ville; in Warren county, dove coloured marbles occur in ledges at the 
head of Lake George; and in Essex county, near Port Henry, is a 
white primitive lime-stone, which will probably be, when properly 
quarried, an excellent and beautiful building stone. 
* Mr. Vanuxem' s Report for 1838. 
