436 PEOCEEDIN"GS OF THE GEOLOGICAL SOCIETY. [Apr. 11, 



this coal, because a large piece from a block of Brown Cannel was 

 given to me a short time ago, which had been brought up by the 

 buckets of the dredge working on the Hunter Eiver, at the shallow 

 known as Eales's Plat, near Morpeth. On my return to Newcastle, 

 and with the knowledge acquired in my examination at Colley 

 Creek, I went to Eales's Mat, and had the place pointed out to me 

 where the dredge had been working; and it is remarkable that I 

 found it to be on the line of upthrow of the porphyries from the 

 Williams Eiver range (which I had long ago traced across the 

 Hunter, near Morpeth), being the extension of the well-known Por- 

 phyry Point, the residence of the late Dr. Carmichael. I therefore 

 conclude that the piece brought up by the dredge, although a loose 

 block, must belong to a deposit not far distant from the place where 

 it was found ; and research will probably lead to the discovery of the 

 seam. 



Geologists have defined that, of Cannel Coals, jet is an extreme 

 variety in one direction, as hatt or carbonaceous shale is in another ; 

 and the specimens which I send will show you that we possess these 

 varieties. 



I have taken the specific gravities of various specimens ; and the 

 richness in oily products will probably be found to decrease with the 

 augmentation in specific gravity, the heaviest leaving the greatest 

 amount of solid residue after distillation. The Hartley stands first 

 as of the lowest specific gravity ; that from Lake Macquarie, a coarse 

 jet, is the heaviest (having a specific gravity of 1*5) ; and that from 

 Colley Creek shows but little diff'erence from the famous Boghead 

 Coal of Scotland, of which I am also able, through the kindness of 

 Mr. Donaldson, to send you a specimen : — 



Specific gravity of Hartley Cannel 1*064 



Boghead 1-160 



Colley Creek M66 



Dredge 1-190 



Stoney Creek 1-289 



Lake Macquarie L560 



Chapapote or Mineral Bitumen from the Cretaceous rocks 



of the south of France 1*158 



Our ordinary coals vary from 1*3 to 1*4. 



The small excess in the specific gravity of the dredge- specimen 

 over that of Colley Creek may be attributed to long contact with 

 water ; it otherwise looks of good promise as a Petroleum Brown 

 Cannel, and, like that of Hartley, ignites readily in the candle-flame. 



The specimens, with the exception of the Chapapote, are all true 

 massive Cannel Coals; and to call them ''Shales'^ is to misname 

 them. 



Besides Colley Creek, I heard of specimens having been picked up 

 in other creeks, at many distant places, particularly on the Warrah 

 Station ; and I can have no doubt that Brown Cannel will be found 

 where the porphyries have tilted up the Lower Coal-measures so as 

 to render them accessible to the miner. The Boghead Coal of Scotland 

 is likewise found low down iu; if not at the base of; the Carbonife- 



