33S Soientifio Intelligence. 



on ; the memoir closes with a chemical and physical study of 

 the minerals collected. Some attention is also devoted to the 

 occurrence and petrography of a number of basaltic cones and 

 extrusions of lava encountered in bis journey. 



The pegmatites occur as a series of seams, dikes, stringers, 

 and lenses, penetrating granites, gneisses, and schists, and their 

 general cbaracter appears to be quite similar to what bas been 

 observed elsewhere in such cases. Here also they often attain 

 gigantic dimensions in the size of the individual crystals. 



The surface of the country, the bill slopes and ridges, as well 

 as the valleys, is nearly everywhere covered by a thick deposit 

 of laterite, resulting from decay of the rocks in place. The 

 pegmatites are likewise changed on the surface, but their presence 

 beneath is revealed by the large unaltered masses of quartz, 

 which form lines of bowlders in the soil. Some of the gem 

 material is found in the soil, but the best occurs in pockets, etc., 

 in the yet unaltered dikes. The chief minerals accessory to the 

 pegmatitic quartz, feldspar and mica which furnish the gems are 

 tourmaline, beryl, and garnet with some spodumene. The tour- 

 malines are mostly black, but splendid rubellites and green, 

 yellow, and brown varieties occur, and, as in other localities, the 

 same crystal often shows zones and bands of several colors. The 

 beryls are sometimes of enormous size and furnish aquamarines 

 as gems ; sometimes they are of a sky-blue color ; there occurs 

 also more rarely a beryl of a peach-blossom color, with a different 

 crystalline form, which makes fine gems (see this Journal, 

 xxxi, 81). The garnet is a yellow variety of spessartite and has 

 yielded some small gems. The spodumene is sometimes lilac 

 (kunzite), sometimes yellowish green, or white. A large number 

 of chemical analyses and determinations of the optical and phys- 

 ical properties of these minerals have been made and the results 

 are given. The whole is a valuable and extensive contribution 

 to our knowledge of the mineralogy of Madagascar. l. v. p. 



11. Production of Phosphate Rock in Florida during 1910. — 

 E. H. Sellards, State Geologist, states in a preliminary circular 

 that the production of phosphate rock in Florida during 1910 

 exceeded that of any preceding year, the output having for the 

 first time exceeded 2,000,000 tons. The total production for 1909 

 was 1,802,151 tons, while for 1910 the production was approxi- 

 mately 2,029,797 tons. This amount includes a production of 

 392,088 tons of hard phosphate rock and 1,637,709 of pebble 

 rock ; the increase noted, therefore, is in the latter variety, the 

 former having diminished from a total of 527,582 tons in 1909. 



12. North Carolina Geological and Economic Survey / 

 Joseph Hyde Pbatt, State Geologist. — The following publica- 

 tions have been recently issued : 



Economic Paper No. 19. Forest Fires in North Carolina during 

 1909; by J. S. Holmes, Forester. Pp. 52, with 9 plates. 



No. 20. Wood-Using Industries of North Carolina ; by Roger 

 E. Simmons, under the direction of J. S. Holmes and H. S. 

 Sackett. Pp. 74, with 6 plates. 



