242 PROCEEDINGS OF THE AMERICAN ACADEMY 



specimens of native phosphate of lime, or apatite, from a large 

 vein discovered by Mr. Alger and himself in Hurdstown, New 

 Jersey, during the month of June last, and offered the follow- 

 ing remarks : — 



" These specimens exhibit, in a striking manner, the various col- 

 ors and forms of this interesting mineral, justifying the name given to 

 it by mineralogists, in allusion to its deceptive appearance. Speci- 

 mens of the crystallized mineral from Bolton, Massachusetts, St. Law- 

 rence Co., New York, Murcia in Spain, and Hungary, were also shown, 

 in illustration of its variable external appearance. The New Jersey 

 specimens were crystallized, massive, and granular, and possessed 

 various colors, such as olive-green, rosin-yellow, brown, and dingy 

 white, and some of them were covered with iridescent films of oxide 

 of iron. The peculiar resinous lustre of the broken surface may be 

 pointed out as most generally characteristic of the mineral. By 

 chemical tests its nature is readily proved, it being at once dissolved 

 in nitric acid, and giving, when neutralized by ammonia, the character- 

 istic yellow precipitate of phosphate of silver when tested with nitrate 

 of silver. The presence of fluorine may also be demonstrated by de- 

 composing the pulverized mineral by sulphuric acid, and allowing the 

 fluohydric acid to act upon glass. 



" Chlorine may be proved to be present by adding nitrate of silver to 

 the nitric solution of the mineral. From these experiments, it appears 

 that this mineral has the usual composition of apatite. Although crys- 

 tals of this mineral have before been observed in the magnetic pyrites 

 of this locality, the nature of the great vein of massive phosphate of 

 lime had not been detected ; its dead white appearance on the surface, 

 and its structural changes into rhombic prisms of 80° and 120°, giving 

 no idea of its true nature." 



Dr. Jackson stated that he had advised Mr. Alger to obtain 

 a lease of this locality, and to work the phosphate of lime for 

 agricultural use, and that mining operations had since been 

 begun, and thirteen tons of the mineral were now on their way 

 to Boston, and would be converted into prepared phosphates. 



He then spoke of the importance of augmenting the propor- 

 tions of phosphates in our soils, and showed that they are es- 

 sential to the healthy growth of both plants and animals. In 



