VJll CONTENTS. 



Page, 

 6, 7. Vegetable Physiology, Circulation of sap — Motion of liv- 

 ing particles in all kinds of matter, - - - 393 

 8, 9. Large still — Production of magnetism by friction, - 394 

 10, 11. Hay converted into a silicious glass by lightning — Flying 



in the air, ------ 395 



12. Formation of hail, - - - - - 396 



13, 14. Expansion of gases — Leonard! da Vinci, - - 397 



Oolite in situ, in Edenville, N. Y. - - - 398 



Hints and Conjectures respecting some of the Causes of the 

 Earth's Magnetism ; by Prof. B. F. Joslin, of Union Col- 

 lege, N. y. - - - - - - ib. 



APPENDIX. 



On the application of the principle of the galvanic multiplier 

 to electro-magnetic apparatus, and also to the developement 

 of great magnetic power in soft iron, with a small galvanic 

 element ; by Prof. Joseph Henry, of the Albany Academy, 400 



ERRATA, AND ALTERATIONS FROM MS. VOL. XIX. 



Art. V. page 46, for C whenever it occurs, read c'. 

 " 49, 5th line from top, for 1, read — 1. 



Page 49, 3d line from bottom, instead of " If the impulses act continually," sub- 

 stitute If the impulses are indefinitely small and act continually. 



Art. IX, page 61, first line, after have read not. 

 Page 135, line 2d from top, for their read these. 



" " " 14th from bottom, for of read to. 



" 136, " 15th from bottom, for professedly read professionally. 



" 137, " 10th from bottom, for design read degree. 



