1890. | "REPORT OF GEOLOGICAL SECTION. 31 
Crump, and a smaller one by Mr. Howell. Mr. Preston showed an 
artificial ruby. 
Mr. Davison exhibited a specimen of granite from near Saratoga, 
which had been changed by the heat of adjacent trap eruption. The 
garnet was changed to chlorite, the orthoclase to kaolin, while the 
mica had become hydrous. 
Dr. Muecke showed a specimen of the red celestite, similar’ to 
those exhibited at former meetings, but surrounded by clay and 
occupying a cavity in coarse sandstone. He also showed a specimen of 
Niagara limestone containing phosphate. 
The topic for the evening, erosion, by rain and rivers, was 
illustrated by lantern views. 
Specimens were presented for identification. 
December 16, 1889. Mr. Davison showed a microscope slide 
which he had prepared from the red celestite brought in at a former 
meeting by Dr. Muecke. Under a magnification of 150 diameters, 
scales of hematite could be seen, measuring =45 m. m. long and a width 
of z45 m. m. to 74> m. m. Under a higher power groups of small 
particles could be seen as points of red light. The red color of the 
mineral was believed by Mr. Davison to be due to the hematite. 
The topic of the evening was waves and tides. Mr. Howell 
described the bar formed at San Diego, Cal., so large as to be laid out 
in building lots. Remarks were made by Mr. Crump and Mr. Howell 
upon the recession of Niagara Falls, and Dr. Muecke spoke of an 
interesting case of erosion at the canal lock at Brighton. 
Several specimens were offered for identification. 
January 5, 1890. Mr. Preston exhibited some chalcedonies, with 
fluid inclusions, found in basalt in Uruguay. Also several minerals 
from northern New York, among which was a fine crystal of altered 
titanite called xanthitane. He had obtained with the latter one 
specimen of titanite which had been changed to steatite, and some 
large rough crystals of titanite weighing from twenty-five to forty-five 
pounds. These were found in a vein of pyroxene, firmly wedged 
between huge crystals of the latter, some being a foot in diameter. A 
fluorite of a beautiful delicate green was shown, being one of a large 
lot found in a chamber in the rock at Macomb, St. Lawrence county. 
The pocket was eight feet below the surface, about fourteen feet long 
and from three to four feet high, the walls completely covered with 
groups of fluor crystals of various shades of green, some over a foot in 
diameter, and transparent. 
