36 CATALOGUE OF PHILOSOPHICAL APPARATUS, &c. 



Drawer 85. Volcanic Tuff with limestone alternating with it. Val de Nera 

 &c., Vicentin. 

 Both containing tertiary shells, of which however the greater part 



^e in Drawer 36 part I. C. 



N. B. Volcanic Tuff is generally defined as an agglutination of fragments of scoriae and 

 loose materials ejected from a volcano, but in reality it appears to be a more homogeneous 

 material than the above description would lead us to infer. Abich states, that the volcanic 

 Tuff of Vesuvius resembles in its composition Pumice, only that whilst the latter contains only 

 one atom of water, white tuff contains 2, and yellow tuff 3 atoms. Palagonite is the name for 

 a kind of tuff met with in Sicily and Iceland. (Vid. infra, p. 40.) 



Drawer 86. Volcanic Tuff with shells of limestone alternating with it, Bra- 

 ganza near Bassano. 

 For the contents of Drawers 81 86, see Volcanos, ch. viii. 



Drawer 87. Volcanic rocks of central Italy near Radicofanr, Acquapendente, 

 and Viterbo. Including columnar trachyte, full of crystals of 



Leucite. 



See Volcanos, ch. ix. p. 151. 



Drawer 88. Suite of specimens illustrating the rock called Peperino. 



This material occurs on the Alban Hills and other places in the neigh- 

 bourhood of Rome, and exhibits the various changes which the 

 volcanic tuff has undergone, as well as the minerals and frag- 

 ments of other rocks which are imbedded in it, so as to form 

 a kind of Breccia. 



What is remarkable is that loose incoherent Tuff lies both 

 above and below this rock near Marino. 



See a notice of a Paper read on that subject at the meeting of the British Association at 

 Aberdeen, by myself, in the report of do. for 1859, p. 102. 



Drawer 89. Volcanic Tuff from the neighbourhood of Rome. 



Two kinds, viz. granular and lithoide, rolled pebbles occur in it. 



Drawer 90. Basaltiform currents of lava from the neighbourhood of Rome. 



Showing (i) the rocks at the Capo di Bove, where the supposed cur- 

 rent terminates. (2) Those nine miles from Rome, on the Appian 

 Road, which seem a continuation of the same current. (3) The 

 second branch of the same current near Vallerano. (4) Similar 

 rock from the ridge bounding the lake of Albano, and from Marino. 

 (5) Leucitic lava of M. Cavo at Hannibal's camp. (6) Sperone, a 

 peculiar kind of tuff near Tusculum. 



See Supplement to "Volcanos," p. 815. 



