192 PROFESSOR BALFOUR ON CERTAIN VEGETABLE ORGANISMS 
that the bodies called by some spores, and which exist in many coals, especially 
cannel coals, may be the larger spores contained in the other sporangia of this 
plant. These fossil spores are large, and appear in the form of a thickened ring, 
probably from the pressure to which they have been subjected. Here, then, we 
seem to have evidence, that Acrogenous fructification is found in coal, leading to 
the conclusion that the plants which produced these sporangia flourished at the 
coal epoch, and aided in the formation of this substance. 
It is probable also, that the inflammable yellow-brown matter which enters 
into the composition of Lycopodes at the present day, and which has caused their 
small spores to be denominated vegetable sulphur, may also have been present in 
fossil plants of a similar nature, and have contributed to form the yellow substance 
which exists in great quantity in some coals. 
A substance derived from the organic kingdom also occurs abundantly in the 
Fordel coal. This is the resin-like matter called Middletonite. This was seen 
about thirty years ago by Dr FLemrne,.in the splint coal of Balbirnie in Fife, and 
afterwards at Clackmannan. Dr Femina is also disposed to think, that certain 
veins of a rich wine-yellow, which occur in Boghead coal, contain Middletonite. 
This organic substance has been described by Professor Jounston of Durham.* 
He found it about the middle of the main coal or Haigh More seam, at the 
Middleton collieries near Leeds. It occurred sometimes in small round masses, 
but more commonly in fhin layers, scarcely thicker than jgth of an inch, between 
layers of coal. In Mr Daw’s specimens, the quantity of the substance is very 
large, occurring both in layers and in granular pieces, and giving a peculiar rusty- 
brown aspect to the surface of the coal. Specimens are seen with several distinct 
layers of this substance, separated by thin laminz of coal of about jth of an inch 
thick, which also seems to be penetrated by the Middletonite. 
Middletonite is hard, brittle, easily scraped to powder by a knife. In small 
fragments it is transparent; by reflected light it shows a reddish-brown colour, 
by transmitted light a deep-red colour. It has a resinous lustre. It blackens by 
long exposure to the air, and then can only be distinguished from the coal by a 
slight peculiarity in the lustre. It burns like resin, and leaves a bulky charcoal. 
In one analysis, Jonnston gives the following composition :— 
Carbon, r sw. ‘ 5 . 86°437 
Hydrogen, . : : : . : 8-007 
Oxygen, < E : : : 6 5563 
On examining this substance, and comparing it with the appearance presented 
by Lycopode powder, as well as with that exhibited by the inner surface of the 
Fordel sporangian valves, J am disposed to hazard the conjecture, that the two 
may be closely connected. It seems not improbable, that the inflammable spores 
* Brewsrer’s Journal, xii, (1838), 261. 
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