110 PROCEEDINGS OF THE INDIANA ACADEMY OF SCIENCE. 



felicity of its descriptions." In it he gives a chart of the Great Illinois Coal 

 Field (Plate IV) which, on a small scale, shows by a map the extent and posi- 

 tion of the coal measures of Indiana. This was the first map of what is noAv 

 widely known as the "Eastern. Interior Coal Field," which covers an area of 

 47,000 sqnai-e miles in central and southern Illinois, southwestern Indiana and 

 northwestern Kentucky. 



First Discovery of Gold in Indiana. 



The next fact of interest which can l)e found recorded regarding the 

 Geology of Indiana was the first mention of the finding of gold in the State. 

 This was in the Journal of the Franklin Institute for June, 1850, and Avas in 

 part as follows : 



"Professor I'razer read to the meeting (of the Franklin Institute, May 

 17, IS.IO) a letter from Prof. T. A. Wylie, of the University of Indiana, an- 

 nouncing the discoverv of gold in the vicinitv of that place, and exhibited 

 specimens of the gold, and of the black sand in which it is found. 'The gold 

 has been found in the beds of the rivulets in Morgan County, about twenty 

 miles northeast; in Jackson County, about twenty miles southeast ; in Brown 

 County, about twenty miles east, and in Greene County, about fourteen 

 miles west of Bloomington, as well as at certain intermediate points, but not 

 in the immediate vicinity. Where it has been found it is always in connec- 

 tion with a black sand which the washers call "emery." This sand is found 

 at the bottom of the streams, usually at the upi)er end of the sandbars or on 

 the margins of the streams where there is a sudden turn, and in such ])laces 

 as it would be naturally deposited on account of its density. Tlie coarse 

 gravel is sifted and washed in the usual way until nothing remains l)ut the 

 dense black sand. On examining closely with the microscope, there are to 

 be perceived interspersed through it red particles of difterent shades, and 

 some few yellow and green particles; of the red particles some appear to be 

 merely r-olored quartz, while others ai;e plainly distinguished by their crystal- 

 line form as garnets, and some of the darkest probably pyrope. Tht; blac^k 

 particles are readily separated into two sorts by the magn(4. Those attracted 

 D.y the magnet, which amount in some specimens to five ])er cent of the wiiole, 

 are evidently magnetic oxide of iron. The remaining black grains agree 

 precisely with Dr. Thompson's description of titaiiatc of iron or menaccaiiite.' 

 The gold is in flat scales, a good deal resembling in ai)|)(;ii-an((' lliat froni 

 California." 



"Professor I'razer remarked that from the account of Professor Wylie, 

 it did not appear that this new gold field was likely to ])rove profitable in the 

 working, but that it was of great interest, both in a geological and mineralogi- 

 cal point of vicAv, and gave rise to an interesting inquiry as to the original 

 locality of the minerals associated AAith the gold, since they are of a nature 

 inconsistent with the rock formations of that ])ortion of the United States." 



