j\6 



THE POPULAR SCIENCE MONTHLY. 



jade, or jadeite — which varies in color from 

 almost milk-white, with a slight shade of 

 green, to a beautiful emerald-green — has not 

 been found in place in America. So far aa 

 is known, all the varieties come from Asia. 

 That it was rare, and regarded of great value 

 among these Central American people, is 

 shown by the fact that they wrought it into 

 finished ornaments with such care, and that 

 to make those ornaments they cut up celts 

 already of value as useful manufactured 

 articles, instead of using rough stones. The 

 question is then in place, whether it is not 

 reasonable to believe that the stone was 

 brought from Asia in the form of imple- 

 ments by the early migrants to this coun- 

 try; and that, as the supply was not kept 

 up, and most likely even its source became 

 unknown, the pieces among the people were 

 cut and recut, and preserved as sacred rel- 

 ics of the past, to be, one after the other, 

 finally buried with their owners ? 



Oscillations of Italian Soil. — 31. Ques- 

 nault read a paper, at the recent meeting of 

 the French Association, on his researches 

 into the oscillations of the ground and the 

 movements of the sea. He had already laid 

 some of his observations on the subject 

 before the previons meeting of the Asso- 

 ciation, and they had been received with 

 favor. He ascribed the changes of level 

 which the ground undergoes to two very 

 different causes : those of one character, 

 sudden and transitory, w T ere traceable to vol- 

 canic phenomena ; others were attributable 

 to sublunary and atmospheric influences. 

 Those more general movements, which mani- 

 fest themselves slowly and regularly either 

 in depression or elevation, could be ex- 

 plained enly on the supposition of an as- 

 tronomical revolution of long duration not 

 yet ascertained, that modifies the center of 

 gravity of our planet and the motion of the 

 (raters that cover it. Professor Issel, of 

 the University of Genoa, presented some 



tabic facts on the modifications of level, 

 both slow and rapid, which the soil of Italy 

 has undergone through a long series of years. 

 Some of these facts, the result of slow and 

 secular movements, are well worthy of at- 

 tention. Thus, tiie Venetian estuary and 

 [stria have been subject during historical 

 times to a sensible depression which amounts 



at Venice to three or four centimetres in a 

 century. The same movement is very evi- 

 dently manifested on the coasts of Dalma- 

 tia, Albania, and Greece, and probably ex- 

 tends across the Mediterranean to Barbary 

 and Egypt. Malta is or has been in the 

 track of the depression. In Sicily, less evi- 

 dently, Professor Issel takes notice of an 

 elevation, which may have amounted to be- 

 tween four and six metres, since 400 b. c. 

 A similar movement seems to have taken 

 place on the Calabrian littoral opposite to 

 Sicily ; but this fact of elevation being com- 

 mon to nearly the whole of the Mediterra- 

 nean basin, we are led to connect it with 

 some astronomical phenomenon rather than 

 with a change in the level of the sea. Pro- 

 fessor Issel also remarks that, while we ob- 

 serve signs of recent depression at certain 

 points of the Italian coasts, other evidences 

 are plainly exhibited of a previous eleva- 

 tion (quaternary), which attained, in Ligu- 

 ria, a height of twenty metres. 



Barometric \TelI«.— Some wells in Mey- 

 rin, Canton of Geneva, Switzerland, have 

 barometric properties. They have been 

 closed at the top, except for a small air- 

 hole, and through this the wind blows in 

 or out, according to the conditions of at- 

 mospheric pressure, sometimes with force 

 enough to make a sound like that of a steam- 

 whistle. If a hat or any light article be put 

 over the hole when the barometer is falling, 

 it will be blown up at once ; but if the outer 

 pressure is rising, the draught will bring 

 leaves and other light objects toward the 

 well. The people of the village understand 

 the action of the wells, and make it their 

 weather gauge. The origin of the phenom- 

 enon is easily explained. It is dependent 

 upon the differences that may be produced 

 at any time between the pressure of the air 

 within the wells and that of the outer at- 

 mosphere. 



A-afu tlda. — The gum asafoetida is de- 

 rived from an umbelliferous plant {Ferula 

 asafoetida) which grows in Persia and Af- 

 ghanistan and other parts of Central Asia. 

 Some information regarding the preparation 

 of the gum is given in Dr. Jaworsky's ac- 

 count of his travels in those regions, which 

 was published during 1S85. The author 



