51 
decrement or iieat. 
enes* with a perfectly lamellar fracture, of a pale olive 
5i-t olTliv 0 tC i C , r - Tstdl) ? cd in Prisms of six planes. The 
I no™, fnf, f^ an< if “ C5tr011ie ly rare at Teneriffo ; ami 
• Ud ' t !' hi tho lavas of Vesuvius; but those of 
: ‘l P - Jfn 'V U a J ,, . n ? d “ llce - Notwithstanding tho great 
vearr l ^ Uocks, which we stojiped to break, to the great 
u our S ll , ldcs > could discover neither nepheliue 
leucite,t nor feldspar This last, which is so common 
m the basaltic lavas of the island of Ischia, does not begin 
to appear at lenenfte, till we approach the volcano. The 
r 1 ° 11 1S n ot columnar, but is divided into ledges 
SO S m. a 40 h ^ kUe3S ’ V lclmed I® the east at au angll of 
oO 01 40 degrees. It bas nowhere the appearance “of a 
current ot lava flowing from the sides of the peak If the 
suppose Ihotlfli o*fh giV w ljh ‘ th t ?. tllese ba salts, we must 
at the ba J of t , th0S, ' b ! 1 tances wh,d » c °mP<ise the Somma, 
effusion n of Vesimus ihey are the effect of a submarine 
eftusion, in which the liquid mass has formed strata A 
few arborescent Euphorbias, the Cacalia Kleinia, and 
Indian hgs (Cactus), which have become wild in the Canary 
tinent of Afwi 83 ^ CS0ld;h ofEurope and the whole con- 
rocks Tli Zi r° the on M P laats "e see on these arid 
on beds if sW JlT n ' UleS werc sli Ppmg every moment 
recognized nZV Ya V. stee P' We nevertheless 
recognized the remains of an ancient pavement. In these 
colonies we discover at every step some traces of that activity 
which characterized the Spanish nation in the 10th century 
siiisSESMi 
eem tnen to be drawing near the mouth of a furnace 
we deSXTZ “ ?’ hen ,> 011 the «»st of Caracas! 
n aeseenc * honi the mountain of Avila to the nort of !• 
threYhundJer^Tft 1 ^* 116 la \ 0t ' tlle dccremci ‘t of heat, 
"udo oTdv hlr 1 fl r y tO i S0S 111 hei 8 ht Produce in this lati- 
■ode only three or four degrees difference in temperature 
ngite. Werner. f Ampbigene.' — Hauy. 
E 2 
