RECENTLY DISCOVERED IN CRAIGLEITH QUARRY. 213 
the excellent description by Mr Wirnam of the structure of Nos. land2. I 
am enabled, however, to make an interesting addition to his account of No. 2. 
When its segments were separated, I observed a cavity of the size of the fist 
at the end of one of them, and a corresponding cavity in the next segment, 
both containing a large quantity of charcoal. This was mostly in extremely 
fine powder. But in scraping the walls there came away small fragments of 
black, light, soft, fibrous matter, undistinguishable from 
common charcoal. By carefully breaking down these 
fragments in Canada balsam, Mr Saprer obtained 
several specimens which exhibit before the microscope, 
on the longitudinal surfaces, the quincuncial punctated 
structure of the pine tribe, as represented in the adjoin- _ Disc-bearing tissue from Craig- 
é ehh ss leith fossil tree. The discs are 
ing figure. JI am not aware that this characteristic jy rsnoed alternate as in Arau- 
structure has been observed before in any of the Craig- —cauria._ ‘The structure is 
a : c : magnified 200 diameters. 
leith fossils since it was described by Mr Nichol in 1834. 
The structure of Nos. 4 and 5 has been ascertained to be also substantially 
the same as that of the preceding fossils. In the case of the Barnton House 
fossil, No. 4, a small transverse slice shows distinctly several little scattered 
portions of methodically-arranged hexangular or deformed cells, separated from 
one another by radiated crystalline masses of fossilising matter destitute of all 
organic form, or by broad black bands, consisting probably of charcoaly cell- 
walls agglomerated by pressure when the crystalliform structure was forming, 
and pushing aside the organic tissue. 

CHEMICAL Composition.—Mr WIrTHAM, without giving his authority for the 
statement, says the fossil found in 1826 was composed in 100 parts, of 60 car- 
‘bonate of lime, 18 oxide of iron, 10 alumina, 9 carbonaceous matter, and 3 loss, 
—that the tree found in 1830, and now in the Botanic Garden, contained 62 
carbonate of lime, 33 carbonate of iron, and 5 carbonaceous matter; and that the 
“fragment and branch” found in 1831, consisted of 37°5 lime, 24:2 oxide of 
iron, and 36°1 coal. These analyses are certainly incorrect. In another analysis, 
supplied by my former University colleague, Dr Witi1am Grecory, the iron 
proved to be 21°8 per cent., apparently in the form of protoxide; the carbon- 
aceous matter, partly coaly, 14:3 when all reduced to the form of charcoal, and 
the earthy matter largely composed of carbonate of lime, with mere traces of 
silica and alumina. These results, besides being incomplete, are in some 
respects erroneous. A subsequent analysis by Mr Roserr Wa ker, briefly 
noticed in Professor Jamrson’s “ Philosophical Journal” for 1834, and referring 
apparently to WirHawm’s fossil of 1830 (xviii. 363), gives the composition as 
carbonate of lime 50°36, carbonate of magnesia 17°71, carbonate of iron 24°65, 
coal, silica, alumina, water 6°15, loss 1:13. This analysis appears to be sub- 
