
PROFESSOR HEDDLE ON THE MINERALOGY OF SCOTLAND. 491 
Bunsen burner had no effect in causing agglutination, even when the crucible 
was inclosed in a jacket. 
The crucible and its contents were now subjected to gradually increased 
temperatures in GRIFFIN’s blast furnace. At a bright-yellow heat there was no 
change, and only when the crucible was at the point of bright ignition, approach- 
ing to a white heat, did the powder coalesce and liquefy. 
According to PovI1tET, this accords with a temperature of 2200° or 2250° Fahr. 
Tending to the conclusion that the depth at which the volcanic force operated 
at the epoch of the Upper Old Red Sandstone was much greater than at the 
time when the Lower Coal was disrupted. 




















AUGITE. 
S. G. Si. ‘Al. Fe. Fe. Mn. Ca. Me. Ko. Na. Hy. Total. 
Malacolite— 
Shinness, white, . 3°15 || 53°06 19| 1°77 47 | ‘15 | 23°63 |19°29| ... ... | 17546 || 100-12 
Totaig, blue, . .| 3:2 |50°69| 03] 93] ... | 07 |25-78/18-09| “5 | 1°43 | 2-62 || 100-12 
Ben Chourn, white, . | 3°16 |/51°59| 11) 33] ... | ... | 22°01/19°59] -49 | 1°01 | 464 || 99-75 
Glen Tilt, white, . 59 BUG MSO ecg uM seed wesee 13 | 22°77 | 18°86) ... sg || ZUG 99°89 
Glen Muick, blue, 3-18 |/51- | ... | 1°37] 1°59] 88 |26-36|17:08| -63| 112] -26 || 99°89 
Sahlite— 
Ben Chourn, é SAV) cei | Se:22 45) |) ae H 3:13] ‘24 | 22°82|}17°58| 44 79 | °42 99°91 
Tiree, . “ 0 5 ons 50°54| 4:69) 4:14 08 “69 | 23°59 | 14°4 “31 63 | 1°48 || 100°51 
Eslie, . : : a ed 49°5 196) ... | 1406 “4 | 24°08 | 10°81 57 8 69 99°86 
Coccolite— 
Gruagach, . é . | 8°05 || 49°04] 6:09} 1°39 | 2:94 46 | 23°34 | 15-12 82 79 | 17 || 100715 
| Diallage— 
Balta, . é : . | 2°96 || 50°23) 5°84] ... 5-22)| ... || 1-23 | 21-59) 1-2 *b8 | 4°17 || 100-07 
Pinbain, : : . | 8°25 51°77) 21 50 2:96 “31 | 221 | 18°46 63 58 | 1:08 || 99:98 
Augite— 
Glen Beg, . : » | 3524 54-20) V7)... 67 "A 119°57 | 16:97) °5 ‘45 | +96 99-96 
Halival, Rum, . . | 8°48 || 50°54] 3°35) 1°34 | 4°42 23 | 21°42 | 17-05 *25 B38 | 71 99°83 
Craig Buiroch, . . | 3°28 || 50°31 | 4°48] 3°92 | 5°76] 31 |17°57| 1662} 19} 89] “38 || 100-45 
Pseudo-Hypersthene— : 
Corry na Creech, green, . | 3°33 || 53°05] 4°82] ... | 11°39) ‘08 | 19°81/11°58| ... oe 63 || 101°34 
Hart 0’ Corry, bronzy, . | 3°33 || 51°36| 1°66) ... 8°97 | 33 | 20°84)16°47|) ... |... 54 || 100°17 
Drum-na-Rabm, . HPS534y Oe WS Or ee eco 25 |19°36|13-85| ... |Ti-88} -2 || 101-25 
Loch Scavig, c . | 8°82 || 49°27 22.) 2-17 | 12°15 38 | 20°26/14°81] ... 30 72 99°98 
Cuchullins (Muir), . | 8°84 || 51°35)... Fi EOS IQaUh ose. 1°84/11°09| ... be 5 98°70 
Skye (Haughton), c ae 50°8 3° anc 9°61] 1°08 | 19°35]15°06] ... 66 | “6 100°16 
Cuchullins (Rath), . | 3°34 || 51°30 76) ... {18°92} :25 | 20°15) 14°85]... ne 21 || 101°44 
Augitic Glass— 
Elie, . , : . | 3°33 || 49°04] 9°71] 1°25 | 516] -81 |16-25)16°38] 31 PE) |) 10001 
John o’ Groats, . . | 3°36 || 46°08 | 11°39] ... 7:92) 46 |16°07/15°65| 82} 1:06 | °38 99-82 





Alteration Products of Augite. 
Conversion into Serpentine. 

All the serpentines of Scotland which I have had opportunities of properly 
studying are metamorphic rocks, formed for the most part by a change of 
| augitic and hornblendic rocks—as diallage, euphotide, and diorite. 
| The serpentines of Unst in Shetland are derived from diallage. Of the two 
