en 
— SS aS oo ees 
350 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 
a coarse sandstone, and the trunks partially buried in the sand. 
Similar petrifactions were also remarked in the Bayudeh desert be- 
tween Ambukol and El Hajir near Abu Samud. 
In several parts of the Thebaid, the Libyan and Egyptian desert ; 
in the saline sandy wastes lymg between the head of the Red Sea and 
the Mediterranean, in the vicinity of the ancient canal of Bubastis, I 
have observed small scattered fragments, with edges more or less 
worn, of silicified wood. Similar fragments have been found in the 
sandy deserts of Abyssinia and Africa even to the vicinity of the Cape 
of Good Hope, and they are said to exist in those of Barbary and 
Morocco. 
The most extensive accumulation known is that in the Suez desert 
near Cairo, which from the number, magnitude and perfect state of 
the fossil trunks has been called the “‘ Petrified forest.” Burekhardt 
has slightly noticed a portion of this tract near Wadi Anseri, where 
he found a great quantity of petrified wood upon one of the hills, 
amongst which was the entire trunk of a tree, supposed by him to be 
that of a date-palm. The latest, and imdeed almost only scientific 
account of this interesting site has been given by M. Limant in the 
‘Bulletin de la Société de Géographie de Paris,’ 2nd series, tom. xiii. 
p- 27. These descriptions would have rendered, perhaps, the present 
‘notice superfluous, had not the result of my observations differed so 
materially as to induce me to commit this trespass on the patience of 
my hearers. 
M. Linant supposes a forest which stood on the spot where the 
trunks now lie, to have been inflamed by a volcanic eruption, and 
shortly afterwards submerged beneath boiling waters, by whose 
agency the trunks while still erect were silicified. The eruption 
continued interiorly and ejected sandstone, both in a fluid state and 
in vitrified blocks, upwards through the argillaceous and limestone 
strata on which they were deposited. This erupted matter reduced 
the petrified trees to a similar state of vitrification. 
In support of this theory M. Linant adduces chiefly the vitrified 
appearance of the sandstone and pudding-stone in the vicinity; the 
loose fragments of these rocks scattered on the surface; the blackish 
aspect of some, as well as of certaim portions of the fossil wood ; 
and the crater-like aspect of the adjacent sandstone hills of Gebel 
Ahmar. 
I will not take up the time of the Society in attempting to refute 
here by a tram of argument, and in detail, these and similar views, 
which perhaps few practical geologists would at this cera of the science 
admit ; but after remarking, en passant, that throughout the memoir 
the occurrence of any acknowledged voleanic product is not mentioned 
(nor was I able to discover such either im situ or im the private mu- 
seums of Cairo), and that the general dark appearance of the sand- 
stone and fossil wood is caused by ferruginous matter common to such 
formations, I will proceed to describe the result of my own observa- 
tions made on the spot during the month of July 1840; apologising 
at the same time for their imperfect nature, and regretting that the 
task has not fallen into abler hands. Pressure of time and the want 
