‘ 
Obfervations on the Fog of 1783. 83 
de Saluces, that it was feen in the Alps at an elevation 
greater than that of Mount Saléve, which rifes 601 toifes 
above the fea. On the 22d of September (1783) I afcended 
the higheft Alps of Dauphiny, to the height of 1660 toifes 
above the fea. (No one has yet been higher in Europe.) The 
fhepherds, who ferved me as guides, all affured me that this 
fog had however paffed over thefe mountains. 
15. The loweft part of the fog was the thickeft and drieft, 
I affured myfelf of this by proceeding from the borders of 
the fea to the fummits of the higheft mountains. 
16. It is probable, according to every account, that this 
fog overfpread almoft all Europe, the iflands of the Mediter- 
ranean, and a part of Africa. It covered the whole Adriatic 
Sea, but extended only to the diftance of 100 leagues on the 
ocean. It was properly a continental fog. 
17. The thunder this year (1783) occafioned great devaf- 
tation. In Provence and Dauphiny alone it killed nearly 
fixty perfons, and a great number of animals. I have found 
no initance of its falling and doing mifchief in places higher 
than 450 toifes abave the level of the fea. - It would be: too 
tedious to infert here the name of every place, which I noted 
down in my journal, where I learned that the thunder fell, 
Jt will be fuficient to relate the moft fingular effects it pro- 
duced, and fuch as may add to our knowledge refpecting the 
nature of thefe terrible meteors, 
According to Pliny, Plutarch, Seneca, &c. the olive, fig- | 
tree, and laurel, are never ftruck by lightning, Porta adopted 
this opinion, which was that of all the ancients. Toaldo. 
fays alfo, it is only thofe trees which contain refin that can 
perhaps efcape the danger of thunder; {uch as the olive-tree, 
laurel, fir, and fome others of the like kind. This, in alk 
probability, is the foundation of the practice, common among 
the populace, of keeping in their houfes, and placing on the 
fummits of fteeples and at the corners of fields, branches of 
alive that have been bleffed, and of burning them in their 
houfes during ftorms. It is poffible, and even probable, that 
trees of this kind may be lefs frequently ftruck by lightning 
than thofe which contain a great deal of aqueous juices ;, but 
} can affert, that thefe prefervatives of the ancients are not 
M 2 equal 
