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of Veins. 357 but are often difpofed in layers parallel to their walls. TT . 3. Veins is the effe£l of depofition from water, and we Ihould per ceive no marks of the materials having been introduced with violence into their place. The Neptunifts cannot obje<ft to the trial of their theory by thefe two fa&s. “ As to the firft, it is acknowledged, that there is a re gular difpofition of the fubftances in mineral veins, but it is one which has hardly any thing in common with the real phenomena of ftratification. It conlifts in the diflri- bution of the principal fubftances in coats parallel to the lides of the vein, each fubllance forming a feparate coat. In a vein, for inftance, containing quartz, fiuor, calca reous fpar, lead, &c. we might expeft to find a lining of quartz crj>ftals, applied immediately to the walls of the mine, and following exa£Uy the irregularities of the fur- face ; next, perhaps, a coat of fluor; then of calcareous fpar ; and laft of lead-ore, in the centre of the vein, the fame order being obferved on the oppofite fide. Thefe fucceflive coats, it is material to remark, are not in planes, but in uneven furfaces, of which the inequalities are evi dently determined by thofe of the walls, that is, of the rock which forms the iides of the vein : neither are they horizontal, but are parallel to the walls, whether thefe be perpendicular or inclined.. Here, therefore, there is no appearance of the aftion of that ltatiifal law, which has dire&ed the arrangement of the other, llrata, and which tends to make the plane of every ftratum depofited by water perpendicular to the direction of gravity. t “ The coating of the veins has, therefore, been per formed under the conduft of fome other power than that ■tv/ liirn