t 422 ] 
trails, "being but little known, though fuch trails feem to 
occupy every where a very conliderable part of the fur- 
face of the earth. I remember to have obferved thefe 
flaty tables, or parallel Jlrata^ of granite, near the top of 
the famous San Gothard, in the afcent of that mountain 
on the fide towards Switzerland. Thefe are alfo 
ranged perpendicularly, like the other common ones in 
granites, and refemble desmarest’s bajaltes en tables % 
affording thus another proof of the analogy remarkable 
between the organization of the different maffes in gra- 
nites, and that of common vulcanic Jirata in general. 
• The former, as well as the latter, have their prifmatic co- 
lumns, their bajaltes en tables^ as desmarest calls them, 
and en boules, as I have obferved in my account of Monte 
Rofib. Surely, therefore, thefe are llrong proofs in fa- 
vour of the common origin of both. The rocks of San 
Biafio abound with ferruginous vitrifications, which are 
frequently ohfervable in granites; and the neighbouring 
tradfswith lava oxpori lgnei\ as I have alfo obferv^ed, when 
I made the tour of this country, particularly about Teolo. 
The Abbe fortis brought me a piece of lapis lenticularis, 
broken from the limefione that fuperficially covers the 
granite of thefe Euganean hills, in many places, as I be- 
fore obferved. I mention this circumflance, recolledfing 
to have taken notice, in my lafi: paper, that fuch figured 
bodies are not commonly found in the lime-flone of this 
country. As the prefent account may ferve, by way of 
appendix, to that which I lately did myfelf the honour to 
prefent 
