164 C. T. Jackson, Esq., on Extracting 



the rock are smoothed out, though their width may be no 

 more than two inches. 



If we now collect all these propositions together in a few 

 words, we obtain the result that, in one of the most recent 

 geological periods, the surface of the land, when it had al- 

 ready obtained its present form, must have been very gene- 

 rally and very thickly covered with masses, which, bear- 

 ing with them sand, and other matter composed of fine- 

 ly-comminuted stone, were urged forward, gradually and 

 slowly, in the same direction ; and which, besides, possessed 

 a certain degree of plasticity, so that they could apply them- 

 selves to the contours of the hills which they embraced, and 

 during their motion could, by their pressure, and with the 

 aid of the interposed sand, smooth and grind away the rocky 

 bottom. 



If, now, concludes Naumann, we finally put the question, 

 to what sort of masses, in the kingdom of nature known to 

 us, such a motion and mode of operation can be ascribed % 

 One answer alone can be given, — that masses of ice resem- 

 bling glaciers are the only agents which appear capable of 

 fulfilling the conditions which were required for producing 

 the phenomena of Hohburg. 



On Extracting Fare Gold from Alloys ; and on the Discovery 

 of Tellurium in Virginia. By C. T. Jackson, U. S., G. S. 



1 . A new method of extracting Pure Gold from Alloys and from 

 Ores ; by C. T. Jackson, U. S., G. S. 



The following method of obtaining pure metallic gold in the form 

 of a spongy mass, has been practised by me for several years, and no 

 account of the process has, to my knowledge, heretofore been pub- 

 lished. It is very useful to the chemist and to the manufacturer, 

 and is more economical than any other method that I am acquainted 

 with. 



After separating the gold from silver, by means of a mixture of 

 nitric and chlorohydric acids, as is usually done, the solution contain- 

 ing gold and copper is to be evaporated to small bulk, and the excess 

 of nitric acid is thus driven off. 



A little oxalic acid is then added, and then a solution of carbonate 

 of potash, sufficient to take up nearly all the gold in the state of 



