26 



PRESIDENT S ADDRESS. 



"It has been stated by some, that the whole appearance of 

 coal_, as seen by the microscope, is that of woody tissue, and that 

 the ashes of all coal show such remains. An extensive examina- 

 tion of coals^ however, will show that they possess a structure 

 essentially of their own kind ; and when vegetable remains are 

 found imbedded in the substance of the coal (as it frequently is 

 without being at all apparent to the naked eye), such structure 

 merely results from a portion of the original tissue remaining 

 uncoalified amongst the mass. Such a condition is shown by 

 three of your specimens — namely, in the Newbottle coal, in the 

 Netherwitten coal, and in Pritchard's specimen. The jets repre- 

 sent still more imperfectly coalified vegetable matter than any 

 form of coal, containing mere vegetable remains ; and perhaps 

 they are the best kind of coaly substance to show, by sections, 

 the various transition states from vegetation to the completely 

 transformed coal. Many coals contain much of the organic 

 remains of vegetation. I send you Dr. Balfour's monograph on 

 the Fordel coal, and also drawings from some sections of vegeta- 

 ble texture I obtained from the Torbanehill — namely, the scalari- 

 form tissue, and the yellow bodies described as the spores or 

 minute seeds of ferns. There are also in many of your other 

 sections, parts which show a uniform homogeneous appearance, 

 as if the substance had become consolidated from being in a 

 plastic or structureless fluid state. The Wallsend coal shows 

 this, and also the Killingworth inferior coal. 



" The South Hetton coal contains a very uniform mixture of the 

 black and yellow matter^ and a more homogeneous texture than 

 any of the others. The splints are all stratified by laminae of 

 the black and earthy matter. The South Shields being almost 

 black, with small elongated yellow cells. The Jarrow is also 

 very black, with the spaces empty of yellow matter. In the 

 cannel, or Parrot coal, we have the greatest variety in the colour 

 and form of these spaces. 



" I have made drawings from many of your specimens, all of 

 which are in the hands of Dr. Richardson, or his printer. 



"Permit me once more to express my best thanks to you 

 for the kind manner in which you so generously offered me 



