120 Notices of Memoirs — Short Notices of Scientific Papers. 



antimony. It contains 6 per cent of antimony, whilst that from 

 Chili, analyzed by Field, contained none ; that from Peru, analyzed 

 by Plattner, 1'61 per cent. ; that from New Granada, analyzed 

 by Taylor, 1-29 per cent. ; that from Colorado, analyzed by Burton, 

 1*37 per cent. 



The mineral was obtained with copper ore from the Morning Star 

 Mine, Mogul District, Alpine Co., California. 



n. Over the Andes and Down the Amazons. — Mr. James Orton 

 records his observations made during a scientific expedition across 

 the continent of South America in 1867.^ The route was from 

 Guayaquil to Para via Quito, Eio Napo and the Amazons. Mr. 

 Orton carried two mercurial barometers (one short, beginning to 

 mark at 9,000 ft.), a WoUaston boiling-point apparatus, and Boussing- 

 gault's ground thermometer. He tabulates more than 60 observa- 

 tions, commencing at the Pacific and rising to Arenal 14,250 ft., 

 Pichincha 15,827 ft, Antisana 16,000 ft., Cotopaxi 12,860 ft., and 

 descending the Amazon Valley to the Atlantic, which, if reliance 

 can be placed on his barometic observations, stands two feet lower 

 than the Pacific, ofi" Ecuador. This he suggests may be due to the 

 attractive power of the great chain of volcanic mountains of the 

 Andes acting on the ocean at their feet. At Panama, he adds, the 

 Pacific and Atlantic sink to a common level, for there the Andes 

 drop down to an insignificant altitude. Mr. Orton's observations at 

 Guayaquil, on the Pacific, were taken in July ; those at Para, on the 

 Amazon, in January, with the same instrument. 



Mr. Orton noticed some singular local variations of the barometer 

 and boiling apparatus on the Amazons, and concludes, that of the 

 two, the mercurial barometer is more reliable than the boiling-point 

 apparatus. The heights, as given by other travellers, express the 

 altitude above the Atlantic ; Mr. Orton has taken the Pacific as his 

 base-line. 



If only we had a greater number of these data to deal with what 

 important and interesting results might we not hope to arrive at. 



III. Geological Notes on the Caucasus. — Capt. F. von Kosch- 

 KULL communicates some interesting Notes on the Caucasus,^ or that 

 region which divides the Black Sea and the Sea of Azoff from the 

 Caspian Sea, and usually called the Isthmus of the Caucasus. This 

 mountainous band unites Southern Eussia with Asia Minor, 



Capt. Koschkull sees evidence, in the valley of the Kur on the 

 Caspian side, and the valley of the Eiver Eion leading into the Black 

 Sea basin, of the remains of straits which formerly united the Black 

 Sea and the Sea of Azofi" to the Caspian. He considers that the 

 upheaval of the Karthlo-Imeritian Mountains and the plateau north 

 of the Elbruz mainly caused the separation of these two basins 

 which now stand at such different levels ; for the Caspian is nearly 

 80 feet below the level of the Black Sea.^ 



1 Silliman's Journal, No. 137, pp. 203-213: 



2 Silliman's Journal, Yol. xlvi.. No. 137, pp. 214-221, and No. 138, pp. 335-347. 

 ^ The Caspian Sea has no inlet, and the waters may owe their depressed level in 



part to evaporation, the summers being very hot. 



