9

Operat ions of Analysis.

analytical chemistry have superseded this ne-cessity ; and it is now universally admitted, thatall the operations of analysis may (in the smallway) be conveniently performed, by the helpof a few instruments, in the closet of the ama-teur of the science; and that even all the appa-ratus, re-agents, and other articles of experiment,necessary for the analysis of minerals, may becomprised in a convenient travelling chest. (SeeIndex MineralOgical Laboratory.)

When the object is to analyse a mineral; forinstance an ore, particularly with a view to as-certain the comparative richness with respect tothe metal it contains, it is absolutely necessarythat specimens of the ore, be taken, from therichest, the poorest, and from that which seemsto be of middling quality. This precaution isindispensible, because were the analysis madewith a rich specimen, it might raise too flatter-ing expectations; or if with a poor one, itmight produce discouragement.

The next step in the analysis of any kind ofmineral, consists in separating the substanceintended to be examined, from all kind of ex-traneous matter, with which it is always moreor less united. They may be separated by pick-ing, washing, or other mechanical operations,