AMERICAN ASSOC/A TION FOR THE AD VANCEMENT OF SCIENCE. 317 



D. W. Prentiss, in Section B, read an interesting paper entitled, "On the 

 Action of Pilocarpin in Changing the Color of Hutnan Hair," which was of great 

 interest. 



Dr. George Sutton, of Aurora, Indiana, read a paper entitled, "The Gold- 

 bearing Drift of Indiana." It gave in detail and in technical language the sup- 

 posed glacial history of that State, and the different directions and paths followed 

 by the different glaciers. 



The paper showed that there is a line of gold-bearing drift extending across 

 the State from Southeastern Indiana in a west and northwest direction to Illinois; 

 and that the drift along this line is comparatively rich in gold, while the gold 

 that is found in other parts of the State is in such small quantities that it is with 

 difficulty that it can be detected. 



There is a vast extent of country on the northern portion of our continent 

 from which glaciers moved, and a large extent of country which has never yet 

 been carefully examined, and I think we are not visionary in saying that we be- 

 lieve it is probable that rich gold veins may yet be discovered beyond the lakes 

 which will give rise to all the excitement incident to the discovery of new gold 

 fields, and the miner, the capitalist, the speculator, the emigrant and the advent- 

 urer may hurry to a region of country which is novv but a barren wilderness, 

 and villages, cities and railroads spring into existence as if by magic, and scenes 

 be enacted in the North similar to that we have so recently witnessed in the 

 West. 



Professor Richard Owen read a paper on "The Unification of Geological 

 Nomenclature." A geological nomenclature has grown up in every country, 

 and almost in every State, and the paper advocated a uniform system. The 

 geologist at present is burdened with many names arising in different countries 

 which indicate the same things. 



The last paper read in this Section was: "Recent Discoveries, Measure- 

 ments and Temperature Observations made in Mammoth Cave," by Rev. H. C. 

 Hovey. The speaker placed before the section a map illustrating the cave, and 

 showed the difficulties of constructing such a map, the chief of which was the un- 

 willingness of the proprietors of the cave to have a correct survey published. 



Mr. Hovey stated that the saltpeter derived from Mammoth Cave, was con- 

 veyed to Philadelphia by mules and in ox-carts, and was the chief source of 

 material for gunpowder used in the war of 1812. This fact has not been stated 

 in a single history of the United States. The author of the paper laid before 

 the section, who extended his time, the results of temperature observations made 

 in 1878 and corrected this month. Sixty temperature observations were taken, 

 of half an hour each, the instruments used being the Casella and Green thermom- 

 eters from the Winchester Observatory. The results obtained are : The lowest 

 temperature in any part of the cave is 52° F.; the highest, 56° F.; the general 

 temperature of the cave may be fixed at 53° F. , which would, of course, be also 

 the temperature of the crust of the earth in the region where the cave is located. 



