504 



On Atmospheric Vibrations, 295 



On Caloric, 342, 355 



On Cresson's Oxyhydrogen Polarizer, ........ 344 



On Photography, ........... 372, 381 



CHEMISTRY. On Thallium 86 



On an Analysis of Delaware and Schuylkill Waters, 146 



On the Deterioration of Ether by Age, 171 



On Assay Balances, ............ 226 



On Magnesium Wire, 458 



GEOLOGY. On the Taconic System, 5 



On the Coal System of Southern Virginia, 30 



On Gypsum Deposit of Southern Virginia, 33 



On Coal Oil, 56 



On a Jasper Cave in New Hampshire, ........ 91 



On the Coal Measures of Cape Breton, 93, 165, 208 



On some Minerals brought back by Dr. Hayes, ....... 139 



On the Progress of the California Survey, . . . .... 182 



On an Asphalt Vein in West Virginia, 183 



On Appalachian Erosion, .......... 194, 



On the Flora of the Coal Measures, 198 



On the Arkansas Conglomerate, .......... 199 



On Balls of Sea-grass on the Shore at Nice, 350 



On the Asjiect of the Abbeville Quarries, 388 



On the Ancient Sea Level, 399 



On Soundings in the Delaware Water Gap, 451 



On a Coal bed in Nova Scotia, 459 



On an old Salt boring in Pennsylvania, 459 



On a new locality of Lignite with Lower Silurian Iron ores, . . . 461, 463 



METALLURGY. On the Use of Franklinite, 88 



PAL.S;ONTOLOGY. Fossils at Phoenisville, 4 



BOTANY. On the Asclepias Fibre, 7 



On Flax and Cotton, 26, 91 



On Sorghum and Imphee, 116, 141 



On Phantom Leaves, ............ 139 



On California Mosses, 234, 412 



On the Tea Plant of Pennsylvania, 277 



On the Growth of the Olive in Spain, 288 



ZOOLOGY. On Buceros Scutatus, 86 



MEDICINE. On the Health of Philadelphia, 26 



On the Progress of the Science, .......... 228 



ARCH.ffiOLOGY. Resume of Morlot, 2 



On the Stone Age in America, ......... 26, 119 



On the Origin of Jasper Arrow Heads, ........ 91 



On the Copper Age in America, . . . . . . . . .110 



On Certain Stone Implements, ....,...- 224, 401 



On Exchanges of Implements with the Academy of Natural Sciences, . 277, 354 

 On Casts to be made by Smithsonian Institute, ...... 281, 412 



On Desor's Discoveries, ........... 413 



On an Enamelled Portrait found at Valley Forge, 457 



On Ancient Pottery in Illinois, .......... 460 



