Veins. III. Befides th'efe repofitories, there is ftill another,- which cannot properly be arranged with any of the fpecies of particular mineral repofitories, and for which we have no name. Thus, ores are fre quently diffeminated through rocks, and fometimes in maffes of greater or lefs magnitude. The fmaller maffes are by miners denominated kidneys, or nejls ; but the larger and more important have not hitherto received any particular denomination. Tin affords examples of kidneys or nefts; and thofe on the great fcale occur in lead-glance, and- it is faid alfo in graphite Second Class. PARTICULAR MINERAL REPOSITORIES, OF POSTERIOR ORIGIN TO THE ROCK IN WHICH THEY OCCUR. We may remark in general, of all the repofito ries of this clafs, that they appear to have been formerly open fiffures, which have been after wards filled up with the foffil materials they now contain. The following are the repofitories be longing to this clafs. I. Veins. Gange.—Werner. Veins are tabalar-Jhaped majfes, having two of their * In the famous lead mine of el Lomo del Toro, in Mexico, maffes of lead-glance mixed with iron pyrites, and weighing 6200 tons, have been cut out of fkm-limeftone.—Soknem- schmid, p. 70.
