280 RE:\rARKs and opixioks. 



tliey conglomerate, rounded forms, as granite 

 frequently does. * 



Out of several places in these porphyry moun- 

 tains break hot springs, the water of which is 

 tasteless and without smell, and deposits upon the 

 stones a slight covering of yellowish-brown stalac- 

 tite. Dr. Eschscholtz found the temperature of 

 one of these springs, which rises in a meadow in a 

 valley, opposite to the entrance of the harbour, 

 between 93° and 9i° Fahrenheit. The stagnant 

 water of several brooks, in the same meadow, de- 

 posits a bright yellow sulphureous sediment. The 

 water of the spring already mentioned, and another 

 on the island of Akutan, in which meat was 

 thoroughly boiled in a short time, seemed to the 

 Doctor to be distinguished by a greater quantity 

 of lime in the water, than in common springs. 

 Another hot spring flows from a layer of real con- 

 glomerate, near Makuschkin at the foot of an insular 

 detached hill, of inconsiderable height, on the sea- 

 beach, below high-water mark. The strata lying 

 on it, of which the hill consists, afford the usual 

 varieties of clay porphyry. 



The Makuschkaia-sobka continues to smoke 

 without any eruption, and the Aleutians procure 

 sulphur out of it. We did not penetrate to the 



* We are indebted to Professor Weisz for most of the 

 geognostical remarks occuring in these essays, and who has had 

 the kindness to examine with the author all the specimens of 

 rock. 



13 



