Its contents. 
2 * NATURAL HISTORY 
The lode is either barren or impregnated. Many of our lodes 
in Cornwall are happily flocked with plenty of metals, but the 
richeft are not equally impregnated in all parts, and numbers of 
lodes have nothing metallic in them : there is nothing conftantly 
uniform in the bowels of the earth ; metals are not more differently 
diftributed among climates and countries than they are oftentimes 
difpofed in different parts of the fame mine. Hence arifes great 
uncertainty and frequent lofs in mining, the certain gain even here 
in Cornwall, where metals are in fuch plenty, being only the main- 
tenance and conftant employment of the labourers and artificers 
depending on the mines, and the confumption of materials which 
bring in a confiderable revenue to the publick whether the adven- 
turers gain or lofe. 
The lode is not fo often two feet wide and more, as it is one foot 
and under ; fometimes however it is wider, but, generally fpeak- 
ing, the fmaller the lode the better impregnated c . 
Lodes either confift of hard, folid ftone, or are lefs compad, loft, 
and crumbly. If the adjoining Jlrata have yielded plenty of liquid 
fpar and cryftal to incruft the metallic particles, then the tin or other 
metal is found inclofed in folid, hard, ftony fubftance ; but where 
nature has been more fparing of her cement, the ore is found in a 
lax, arenaceous, and rubbly ftate : both hard and foft lodes may 
be well and equally impregnated, but foft lodes are more apt to 
have their metals difperfed. 
sect. vi. Lodes are feldom perpendicular; they decline as they defcend, 
The inch- either to the right hand or to the left, but in very different degrees ; 
j^ure^of and the fame lode may decline in one part to one fide of the per- 
their°caufe nd P en dicular, aud in another part to the oppofite fide. This decli- 
nation increafes as it approaches the fides of hills, and the cliffs of 
the fea-fhore, of vallies and of rivers ; but the fame lode which 
fhelves away quick at the declivity of a hill, or the approach of a 
precipice, when it gets upon a champaign plain ground, coafts it 
almoft upright. Again : Lodes are not only inclined but fractured, 
and the inclined fragments found feparated from each other by the 
intervention of earth ftone, or both, entirely different from the 
lode ; from whence it follows, firft, that fuch lodes were formed be- 
fore the fradure ; fecondly, that as the fradure muft have been the 
effed of violence, and probably ‘of a violent agitation, the inclination 
muft have been alfo the effed of force, although in many inftances 
that force only bent, and did not proceed to that degree of violence 
as to occafion a difrupture of the lode ; thirdly, the firft diredion 
of 
c Ip the parifti of St. Juft (Penwith) the lodes are feldom wide, but the tin. is of the beft kind. 
