Tfioughts upon the Mature of Heat and Electricity. 367 



Ihem to be mere nodules of iron and clay. The following are the 

 forms in which they most generally appear.* 



No. 1. Body simple, free, funnel formed, concentrically lami- 

 nated ; interior filled with extraneous matter ; exterior rather 

 smooth ; pedicle rather long, tapering, bent slightly, and perfo- 

 rated ; the whole beset with a few, remote, thorn-like points. 



No. 2. Body tuberose, hollow ; pedicle very short, bent, and 

 perforated. Laminas and points as in No. 1. 



No. 3. Body cup-formed, hollow, and termination papillous; 

 no pedicle, the points very remote. 



No. 4. Body ovato-oblong, apex obtuse, smooth, pedicle short, 

 no points, perforation entire. 



No. 5. Body subglobose, with many protuberances ; no pedicle 

 or points, perforated. 



No. 6. Body sub-cylindrical, transversely striated, perforated 

 throughout, no points. 



THOUGHTS UPON THE NATURE OF HEAT AND ELECTRICITY. 



To the Editor of the Monthly .American Journal of Geology, &c. 



Sir, — The following remarks are drawn up rather with the 

 hope of attracting attention to an obscure subject, than to display 

 original views. They are the sum of considerable reading upon 

 electricity, &c. without claiming scientific experiment as their 

 basis. But hints often strike out sources of thought ; and if these 

 remarks can do that, they effect the whole design. 1 place 

 them in your Journal because 1 wish it success, and because I 

 am a subscriber. 



Among many other bodies, the tourmaline is capable of display- 

 ing electrical phenomena. Heat, however, is necessary for this 

 purpose, apparently offering an evidence of the intimate con- 

 nection between heat and electricity, though it does not extend 

 to a satisfactory argument, for the theory that they are distinct 

 forms of matter. It may be presumed that electricity exists in 

 the crystal, and that heat developes it. There is certainly nothing 

 absurd in this view, though it may appear too exaggerated an 

 idea to arise from such insufficient reasons. The connection, 

 however, between them is immediate, and something more than 

 • See Plate. 



