XIV 
less mixed with the rock but aggregated on similar lines, and 
thus forming veinules equally minute in the slate.* 
Copper and several of its ores impregnate the granite,t 
elvan,t and slate§ im much the same manner as tin-ore impreg- 
nates them, but less frequently. 
Neither the particles which are scattered through the rocks 
nor the minute veins which intersect them are, however, of much 
—if, indeed, they are of any—economic importance. 
In Cornwall the principal repositories of metals and ores are 
the Jodes,|| which consist in great measure of quartz; but—ex- 
tending, without let or interruption, through every rock of the 
metalliferous series, and partaking the mineral character of each 
in its turn—always contain more or less felspar also. Notwith- 
standing the works. in adjoming mines{ often extend for con- 
siderable distances on Jodes in corresponding directions, it is by 
no means certain that any one individual lode has been traced for 
more than about a mile in length. In fact, every lode throws off 
(so to speak) into the adjoining rocks branches and. strings in such 
abundance that instead of a single champion-lode,** it and its con- 
geners form rather a complex and irregular net-work of veins. 
Often, too, the lode first discovered dwindles to a mere line, whilst 
some of its off-shoots enlarge, and equal, or even exceed, both in 
size and richness, the vein from which they have separated. It 
is, perhaps rather more common for lodes to split as they are 
followed eastward, than the contrary. It is by no means unusual 
for them to divide immediately at their intersection by a cross- 
vein ; on one side of which they appear united, but on the other 
in several branches. The lodes and branches which thus traverse 
the rock,—although they are not accurately parallel,—may, on a 
p. 5., Pl. ii., Figs. 1,2. Hawkins, Cornwall Geol: Trans: i., p. 140. Carne, 
Ibid, ii., p. 79. Dela Beche, Report, p. 175. Henwood, Cornwall Geol. 
Trans., V., pp. 31, 37, 38, 85, 164-165. 
* Rashleigh, British Minerals, ii., p. 6, Pl. ii, Fig. 5. Carne, Cornwall 
Geol: Trans: li., p. 84. Boase, Ibid, iv., pp. 251-253, 440. De la Beche, 
Report, pp. 316, 317. Henwood, Cornwall Geol: Trans: v., pp. 101, 135, 
238-240; Pl. xi., Figs. 1, 2, 3. 
+ Henwood, Cornwall Geol: Trans: v., p. 73. 
+ De la Beche, Report, p. 182. 
§ Henwood, Cornwall Geol: Trans: v., pp. 73, 98, 239. 
|| Borlase, Natural History, pp. 142, 147. Pryce, Mineral: Cornub: 
pp. 77-95. Phillips, (W.), Geol: Trans: ii., pp. 126-133. Carne, Cornwall 
Geol: Trans: ii., p. 51. Boase, Ibid, iv., pp. 439-442. De la Beche, Report, 
p. 318. Henwood, Cornwall Geol: Trans: v., pp. 174-1753 vili., pp. 675, 
705-706. Von Cotta, Ore-Deposits, pp. 26, 412. 
q Henwood, Cornwall Geol: Trans: v., p. 175. 
** The larger lodes are provincially called Champion-lodes. 
