234 PROFESSOR HEDDLE ON THE MINERALOGY OF SCOTLAND. 
I would propose the term corded structure for what has been described ; 
and I adopt to the full Nicor’s view, that two substances of a nature differing 
both in composition and molecular segregation,—differing also unquestionably in 
- the system of crystallisation to which they belong, have here harmoniously united 
in one structure, in which the rectilinear rigidity of crystalloid arrangement is 
pervaded but not infringed by the flowing curvatures and wavy lines of a struc- 
ture as involved as the anastomosis of plant or unimal life. 
I must, however, refrain from proposing a name for the crystals which exhibit — 
this structure, until their optical properties disclose whether the included sub- 
stance is albite, or, as I suppose, oligoclase ; should it prove to be albite, these 
are all, of course, microlines; should it be oligoclase, the crystals have the 
same claim as that mineral to a specific name. 
Of the two appended columns, the first enumerates some of the felspars in 
which the structure is clearly to be seen ; the second, those in which it is clearly 
absent. The latter are, in fact, few in number. 
From Corded. Plain. 
anaes rela eerie Ben Capval, Harris. Rispond, Sutherland. 
Mah I pier ota, aang ST do. Hillswick, Shetland (?) 
nelss. . . 
Scaire Ruidh, do. 
West Stocklet, do. 
Shermaig, Sutherland. 
Felspathic layers of do. { Enribol, do. 
Cape Wrath, do. 
Exfiltration veins in do. 
Intrusion veins in Micaceous 
Gneiss. 
Felspathic layers of do. 
Intrusion veins in Granite. 
Exfiltration veins in do. 
Drusy Cavities in do. 
Syenite, “ : 
Granular Limestone, 
Felsite, 
Porphyry, 
Tufa, 
Pitfechie, Aberdeen. 
Blirydrine, Kincardine. 
Midstrath, Aberdeen. 
( Brathans, Kincardine. 
Struay, Ross. 
Ben Resipol, Argyll. 
Rubislaw, Aberdeen. 
{ Cove, Kincardine. 
( Rubislaw, Aberdeen. 
| Yestnaby, Orkney. 
{ Tongue, Sutherland. 
| Anguston, Aberdeen. 
| Cairngorm, Banff. 
Upper Craigton, Aberdeen. 
{ Arran ? 
{itech Ross. 
Eslie, Aberdeen, 
a 


?Glen Urquhart, Inverness. 
Cowbhythe, 6th vein, Banff. 
Amazonstone, Ross.* 
Stromness, Orkney. 
Froster Hill, Aberdeen. 
Glen Beg, Inverness. 
Hausemann, Kincardine. 
Skaw, Unst, Shetland. 
{ Canisp, Sutherland. 
Sanidine, Fife. 
* This consisted of a single crystal of nearly an inch in size, imbedded in granite—or part of a 
granitic veiu,—it was found and given to me by the late T. Bell of Ballygrogan. 
has escaped my memory. It has a pale but fine green colour. 
The precise locality 

