May 7, 1897.] 



8GIENCE. 



725 



two different strata of growth, but botli 

 purely and originally European and Gre- 

 cian. The influence of the Orient was late 

 and slight. The two early migrations may 

 be called Danaan and Achaean ; but the 

 chief fact remains that they were both of 

 indigenous cultural development, not im- 

 ported or exotic. 



What is more, the later, historic Greeks 

 directlj"^ inherited this culture, as is proved 

 by the identity or close similiarity of archi- 

 tecture, ornament, pottery, arms, and relig- 

 ious and political institutions. This also is 

 asserted by Homer and all early Greek tra- 

 dition. 



The linear and hieroglyphic writing, 

 scantily represented in the Mycenean 

 horizon, may point to Asiatic fonts; rather 

 Anatolian (Hittite) than Phoenician ; but 

 the evidence is too slight to speak finally 

 on this question. 



D. G. Beinton. 



University of Pennsylvania. 



NOTES ON INORGANIC CHEMISTRY. 

 A PAPEE was recently read before the 

 Royal Society, by Dr. W. A. Tilden, on the 

 gases enclosed in crystalline rocks and 

 minerals. From the time of Brewster, ob- 

 servers have found in many crystallized 

 minerals, notably in quartz, cavities con- 

 taining gas, and often drops of liquid. 

 Water, carbon dioxid, hydrocarbons and 

 nitrogen and, more recently, hydrogen 

 and carbon monoxid have been found. 

 A large number of crystalline rocks — 

 granite, gneiss, basalt, etc. — have been ex- 

 amined by Dr. Tilden, and the yield of gas 

 varied from 0.65 volumes, in a recent (1760) 

 lava from Vesuvius, to 17.8 volumes, in a 

 gneiss containing corundum from Serringa- 

 patam. The gas is apparently contained in 

 cavities which are visible in thin micro- 

 scopic sections, but that these cavities are 

 extremely minute is shown by the fact that 

 there is practically no diminution of yield 



when the rock has been reduced to a coarse 

 powder before heating. The largest portion 

 of the gas is carbon dioxid and hydrogen, 

 with nitrogen, methane, and carbon monox- 

 id, each to the extent of a few per cent. In 

 no case was any evidence of helium found. 

 The presence of hydrogen and carbon 

 monoxid is accounted for by the formation 

 of the rock in an atmosphere rich in steam 

 and carbon dioxid, which was or had been 

 in contact with an easily oxidizable sub- 

 stance ; this might be metallic iron, which 

 has been found in basalts and other rocks. 

 The presence of marsh gas in the rocks 

 tends to support the view that in the in- 

 terior of the earth's crust there are large 

 masses, not only of metal, but compounds 

 of metals, such as iron and manganese, 

 with carbon. This view, first put forth by 

 Mendeleef, which would account for the 

 great deposits of natural gas, petroleum 

 and other natural hydrocarbons, appears to 

 be steadily gaining ground, and has received 

 further support by the work of Moissan and 

 others on the metallic carbids. 



Maueice de Thierry communicates to 

 the Comptes Rendus determinations of at- 

 mospheric ozone on Mount Blanc, begun in 

 1894. At Chamounix the amount of ozone 

 was 3.5 mg. per 1,000 cubic meters of air ; on 

 the Grand Mulcts (elevation 3,020 meters), 

 9.4 mg. , or nearly four times as much as at 

 Paris. The conclusion is drawn that the 

 amount of ozone increases with the eleva- 

 tion, a confirmation of earlier results. Hail, 

 falling at an elevation of 4,200 meters, 

 when placed on a sheet of iodo-starch ozono- 

 scopic paper gave immediately circular 

 violet spots of larger diameter than the 

 hailstones and paler in the center, but it 

 was not determined whether these spots 

 were due to an atmosphere of ozone sur- 

 rounding the stone, or to hydrogen dioxid 

 from the melting hail. Neighboring snows, 

 however, have never shown a reaction for 

 hydrogen dioxid. 



