The reading of this paper gave rise to much conversational 
discussion amongst the members. Several objections to the 
use of gun-cotton were brought forward by Mr. Stoddart, 
Mr. Ferris, and others, which applied, however, only to 
Schonbein's product, and not Von Lenk's. Mr. W. P. King 
imentioned that at the close of the Italian war a large quan- 
tity of gun-cotton remained for a long time at the Post- 
-office at Trieste, exposed to heat, &c., without any damage 
ensuing. The President stated how useful he considered it 
would be in blasting conglomerate rocks, as gunpowder 
frequently exploded from the holes as from a gun-barrel, 
without splitting the rock. Mr. E. A. Praeger gave some 
interesting details of the mode of military mining, which 
[exemplified the great advantage of gun cotton: and stated 
that he bad recently heard from Prussian and Austrian 
[officers that they were perfectly satisfied with its perform- 
ances, and should use nothing else. 
The President then exhibited a fossil, found in the lias 
at Kelston by the Rev. Mr. Poynton, which he had been 
iasked to examine, He described the modes of determining 
the nature of the fossil— proceeding negative!}' as it were — 
'and gave it as his belief that it was the portion of the stem 
of an Equisetnm, probably Hippurites, which had hitherto 
only been found of one inch diameter, while the specimen 
shown was fully double that size. Mr. Leipner was more 
disposed to regard it as a gigantic reed. 
Mr. Leipner, the bon. secretary, made a few remarks 
upon a specimen of the Lemuridae lately presented to the 
Institution, from the West Coast of Africa, The Lemuridae 
belonged to the Quadrumana, possessing opposable thumbs, 
but were the lowest of the class, and the nearest to 
quadrupeds. This specimen had the forefinger on the fore 
extremities reduced almost to nothing, only the pharyngeal 
joint being evident, and on the hinder hands the fore finger 
had a distinct claw. He believed that it was identical with 
the Peroditicus Geoffroyi of Bennett, which was described 
as nocturnal, and living on vegetable diet, though this 
specimen had a strongly developed canine tooth. 
I WM. LANT CARPENTER, 
Honorary Reporting Secretary. 
