Winslow.] 20 [October 5, 



thought similar preparations of the internal organs might be 

 made. He doubted if any of these solutions would preserve 

 colors permanently, but if a preparation could be discovered 

 which would preserve the form perfectly, he would be willing 

 to dispense with color. 



The following papers were read : — 



Letter from Dr. C. F. Winslow, containing a Description 

 or a Deep Excavation in the Valley of the Ehine, 

 near the mouth of the neckar, and of a mortar- 

 shaped Pebble found twenty-five Feet below the 

 Surface. 



Heidelberg, Baden, March 31, 1868. 



This afternoon I walked with my friend, Mr. William H. Wahl, 1 

 of Philadelphia, a scientific student at the University here, to show 

 him a deep excavation or gravel pit in the flat valley of the Rhine, 

 and give him some idea of the water action by which these valley 

 deposits have been made. The spot which we explored is on the 

 road to Schwetzengen, and is about one mile, or one and one-half 

 miles from the base of the mountain south of the Neckar. The gravel 

 pit is a short distance west of the railroad crossing, and on the south 

 side of the road, or common highway. 



The deposit consists of: 



1. Silt, fine and dark yellow, with many helices irregularly inter- 

 spersed, and some small pebbles rounded and angular, extending in 

 irregular, horizontal lines or laminations, with two or three large, 

 angular, or partially rounded stones, or boulders of granite and red 

 sandstone, similar to the granite and red sandstone existing in the 

 Neckar valley. (The silt is of the same character as that composing 

 in many places the surface of the valley of the Rhine, and which 

 crops out on the north banks of the Neckar, and which I have ob- 

 served constituting banks of considerable thickness on the flanks of 

 the hill, both north and south of the Neckar valley, and in the 

 Neckar valley east of Heidelberg.) This deposit varies from two to 



1 Mr. Wahl soon after graduated at Heidelberg with the first honors of that Uni- 

 versity, and is now (Aug., 1870) a Professor in the Franklin Institute, and an Asso- 

 ciate Editor of the Journal of the Franklin Institute, Philadelphia. 



