1884.] NATURAL SCIENCES OF PHILADELPHIA. 279 



" Descriptions of New Species of North American Heterocera," 

 by Herman Strecker. 



" Some Notes on the Movements of the Androecium in Sun- 

 flowers," by Dr. Asa Gray. 



" Observations on Cinna, with Description of a New Species," 

 by F. Lamson Seribner. 



Fired Stones and Prehistoric Implements. — Dr. D. G. Brinton 

 exhibited specimens of quartzite, sandstone and jasper, which had 

 been subjected to the action of fire, and spoke of their bearing on 

 certain archaological questions. 



The most ancient evidence of a knowledge of fire is not the 

 charcoal and ashes of primeval hearths, but stones showing the 

 action of the element. In France they have been found in con- 

 siderable numbers in the tertiary deposits of Thenay, near Pont- 

 levoy, belonging to the late miocene or early pliocene. In South 

 America, the brothers Jose and Fiorentino Ameghino have dis- 

 covered them in a low stratum of the Pampas formation, believed 

 to be referable to the interglacial epoch of the pleistocene. 



The effects of fire on stones are quite distinct from those of 

 other agents. They are shown in discoloration, scaling, and 

 peculiar forms of fracture. Quartz becomes cloudy and opaque ; 

 jasper loses its fresh yellow hue to turn a dull red, while sand- 

 stone forfeits the fresh lustre of its fracture, and shows brown 

 and blackish. 



Stones broken by fire present one of two characteristic ap- 

 pearances ; the one is called by French archaeologists Craquel- 

 lage, the other Etonnement. Quartzite illustrates the former, 

 jasper the latter. Graquellage presents a plane usually at about 

 right-angles to the plane of cleavage; its surface rough, friable, 

 and full of little pits and rounded eminences — like a face pitted 

 with small-pox, to borrow the simile of Mortillet. Etonnement 

 is a splitting by flakes in the lines of percussion cleavage, but 

 distinguishable from the latter by the absence of the bulb of per- 

 cussion, and the splintering which often attends a blow. The 

 flake and its matrix are perfectly clean at all points of their 

 edges. 



Scaling is seen on the surface of sandstones subjected to fire. 

 Small scales are loosened and are detached by exposure, revealing 

 the discolored layers beneath. 



It is claimed by some of the French archaeologists that the 

 very oldest implements used by man were stones thus fractured 

 by fire. This plan of bringing them to an edge, they saj^, pre- 

 ceded that of percussion. This does not appear to be the case in 

 America. The implements of the Trenton gravels are of sand- 

 stone chiefly ; those of the interglacial of the upper Mississippi 

 are of quartzite, neither of which fractures by Etonnement. 

 Whether the later residents of our soil ever used fire to aid their 



