CONTENTS. 



4. Concerning the Odours developed by the Thunder- 

 bolt, .106 



6. Lightning instantly melts many substances, and pro- 

 duces immediate vitrification, it shortens those me- 

 tallic wires along which it runs, and pierces holes 

 in the bodies it encounters in its progress, . .106 



6. On the transportation of masses of matter effected 



by Lightning, 107 



7. Lightning cleaves wood in the direction of its length 



into a number of thin laths, or into still smaller 

 fragments, „ 109 



8. Upon the dangers which arise from Lightning, and 



upon the means which at different times have been 



used for protection, more especially conductors, 114 



1. Are the dangers which arise from Lightning 



so considerable as to merit consideration ? 114 



2. On the means which mankind have em- 



ployed for personal protection against 

 Lightning, . . . . . .124 



3. When Lightning falls on Man or .Animals, 



placed near each other, whether in a straight 

 line or in an unenclosed curve, it is gene- 

 rally at the two extremities of the line that 

 its effects are most intense.and hurtful, 132 



4. Is the risk of being struck increased by run- 



ning, during a thunder-storm ? . .138 



5. Are the Clouds whence Thunder and Light- 



ning are incessantly issuing so constituted, 

 as some natural philosophers suppose, that 

 it is very dangerous to traverse them ? 140 



6. Does the Lightning strike before it becomes 



visible? 143 



IV. On the Geology of the Neighbourhood of Kelso. 

 By Charles Le Hunte, Esq. In a Letter to 

 the Editor, ..... 144 



V. A singular mode of Propagation among the Lower 

 Animals illustrated. By Sir John Graham Dal- 

 YELL. Communicated by the Author, . 152 



VI. On Geodetical Surveying and Trigonometrical Level- 

 ling. By WiLUAM Galbraith, Esq. M.S. A., 

 Teacher of Mathematics in Edinburgh. Com- 

 municated by the Society of Arts for Scotland, 158 



I 



