results of the test for refraction, posed of about 53 parts sulphur to 47 iron. Itisa rest—adjusted for parallel rays; and this ophthalmolo- but the letters used should ‘be proportionately small if pale, sometimes bright, yellow mineral, nearly as hard gists claim can only be secured by placing… … by the axes of its cylindrical lenses can be in pyrite, it is always well to ascertain by placed in any degree of a circle beforethe analysis if enough gold is there to pay eye tube. The disks are so situated that for working. the lenses of one can be interposed with . Though pyrite contains nearly…
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