1869.] 267 [Jackson. 



Dr, C. T. Jackson announced the discovery of a new local- 

 ity for tin ore in Winslow, Maine. 



Mr. Daniel Moore of Waterville, Maine, has recently sent me some 

 samples of tin ore, discovered on the farm of Benjamin Furbur, one 

 and a half miles below Winslow bridge on the road to Augusta. 



The rock in which the veins exist is a compact mica slate or gneiss, 

 and the vein stone consists of fluor spar (of a purple color), silvery 

 radiated mica in hexagonal prisms and quartz. A little granular 

 arsenical iron or mispickel, is found in the quai'tz, and some patches 

 of yellow copper pyrites. 



The tin ore is tlie brown tin stone or cassiterite (oxide of tin colored 

 Avith oxide of iron), and the ore is crystallized in modified quadrangu- 

 lar prisms, which are pretty well terminated, and in hemitrope crystals 

 or macles of larger size than usual. 



The bed rock is reported by Mr. Moore to be eight feet in width, 

 and as having a course of northeast and southwest. The fluor spar 

 veins are re^iresented to be from one half inch to one foot wide, and 

 they carry the tin ore. The number of these veins is stated to be 

 from twelve to fourteen, and most of them contain tin ore in scat- 

 tered crystals. 



I have made the following assay of the tin ore. After reserving the 

 samples, which I now exhibit to the Society, I took the rest of the 

 ore (which, after being pulverized, Aveighed three hundred and thirty- 

 three grains), and washed it down to one hundred and seventy-five 

 grains of concentrated ore. This, digested with a mixture of nitric 

 and chlorhydric acid, until all matters soluble in acids were removed, 

 and the tin ore which remained undissolved, was collected on a filter, 

 washed, dried, and weighed one hundred and sixty-three gi-ains. 



This reduced in a crucible lined with lamjiblack, and the tin puri- 

 fied by melting it with borax, gave seventy-five and one-half grains 

 of pure metallic tin, or 46.32 per cent., on the concentrated ore. 



It is a satisfaction to be able to announce the discovery of a real 

 tin mine, after having seen so many pretended discoveries of this ore 

 published, -which had no mineral foundation. It is to be lioped and 

 expected that when people learn to recognize tin ores, that more 

 localities of them will be discovei-ed, especially in the New England 

 States where there are obvious geological indications of their ex- 

 istence. 



