18g4.] natural history society. 373 



Proceedings. 



The first paper, entitled " Notes on the Geology of Eastern 

 New York, by Prof. James Hall and 8ir W- E. Logan," was 

 read by Dr. T. Sterry Hunt. This paper is printed in the 

 present number. 



Dr. Hunt then made a verbal communication on phosphate 

 of lime; he described its nature and composition generally, its 

 sources in nature, and its various uses, particularly as a manure. 

 After noting the manufacture of superphosphate of lime from 

 bones, coprolites, and guano, he proceeded to describe the supplies 

 of the phosphate of lime known to mineralogists as apatite, which 

 is met with in crystalline rocks and especially in Canada ; where 

 the mineral is found abundantly in the vicinity of Perth, and also 

 at several points along the Ottawa. The phosphate occurs both 

 disseminated in small crystals through certain beds of crystalline 

 limestones of the Laurentian system, and in regular veins which 

 intersect the rocks of the same system. In these veins the mineral 

 is sometimes found nearly pure, and at other times associated with 

 pyroxene, large crystals of magnesian mica (which are wrought),. 

 and other silicated minerals. Not unfrequently also it is mingled 

 with lamellar carbonate of lime, which sometimes so far predomi- 

 nates as to give rise to what may be called a crystalline limestone, 

 holding grains and crystals of apatite, and can scarcely be dis- 

 tinguished from those stratified Laurentian limestones of the 

 region, which also contains apatite, except by the fact that it 

 occurs in veins, cutting the strata. Many of these are too poor 

 in apatite to be wrouglit with advantage ; but Dr. Hunt expressed 

 the opinion that all the workable phosphate of the region occurs 

 in true veins, some of which are of considerable width, and are 

 filled with phosphate of lime almost without any foreign admixture. 

 Dr. Hunt then proceeded to give a history of these deposits, which 

 were first described in 1848, in the report of the Geological Sur- 

 vey, the ofiicers of which had since, on repeated occasions, called 

 attention to the value of this material, and had shown it at the 

 great exhibitions of London and Paris. He then described the 

 attempts now being made to work the deposits of this mineral by 

 some New York capitalists in North Burgess, where they have 

 forty or fifty workmen. undiT the direction of a skillful mining 

 engineer. 



Vol. I. z No. 5. 



