from the Coal Measures of Torhane-hill. 35 
informed that the Microscopical Society of London is " a 
learned body, who make it their object to pry into all things/' 
I cannot be silent ; but 1 would have you keep in mind that 
my sole motive in now appearing before you, is, the cause 
of truth, and in this cause I come forward fearlessly, but 
honestly, to state that the Torhane-hill mineral is not, micro- 
scojncally speaking, a Coal ; that it is not like any of the combus- 
tible substances used in this country as Coal ; and that, although 
possessing some of the properties of Coal, it is, notwithstanding, 
a mineral sui generis, having a basis of clay lohich is strongly 
impregnated with a peculiar combustible principle, and that when 
plants are found in it, they are accidental, and have no more been 
concerned in the formation of the mineral than has a fossil bone 
in thai of the rock in which it may be imbedded. 
1. External characters of the Mineral. — Of these you will 
have a good general idea from the specimens on the table before 
you. It frequently occurs in seams of some considerable 
thickness, and always in the neighbourhood of coal, some- 
times in immediate contiguity with it, but at other times, 
according to Mr. Ansted, separated from it by a laj^er of fire- 
clay. The colour is generally a dark brown or black, without 
lustre, but varies according to its position in the seam ; 
its specific gravity is qj. i_3_^ water being as 1. When 
scratched with a knife it exhibits a brown streak, in which 
particular it is said to differ from all the known coals with one 
or two exceptions. It is tough and not so brittle, but that 
very thin sections may be made of it, and when struck with a 
hammer, it emits a dull sound; the remains of plants, espe- 
cially Stigmarice, are of constant occurrence, and can be dis- 
tinguished by the naked eye without difficulty. 
2. Characters exhibited under the Microscope. — When a 
small chipping or fragment, about half an inch square, is 
examined as an opaque object under a power of 40 or 50 
diameters, it will be found to consist of masses of a yellow 
material, some being of irregular figure, others more or less 
rounded, imbedded in a granular matrix, varying in colour 
from a yellowish-brown, almost to black. The whole of the 
mineral appears to be composed of granules of various sizes, 
and although the part which has been termed the matrix is 
black, this also will become brown if the surface be scraped. 
The scraping can readily be done under the microscope whilst 
the fragment is being inspected ; and, curiously enough, both 
the surface of the mineral, and the minute particles scraped 
off, assume a light-brown colour. Portions of plants imbedded 
in the mineral can, by the process of scraping, be readily 
distinguished from the impressions of plants ; the former are 
