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color to paper. The leaves of the laurel, common cabbage, and the grasses, are found sufficiently senstive. Common Merrigold yields an invaluable faecula, which appears identical with that produced by the Wall-flower, and Cochorus japonica mentioned before, and is very sensitive, but photographs procured upon it cannot be preserved, the color is so fugitive. From an examination of the researches of Sir John Herschel on the coloring matter of plants, it will be seen that the action of the sun's rays is to destroy the color, effecting a sort of chromatic analysis, in which two distinct elements of color are separated, by destroying the one and leaving the other outstanding. The action is confined within the visible spectrum, and thus a broad distinction is exhibited between the action of the sun's rays on vegetable juices and on argentine compounds, the latter being most sensibly affected by the invisible rays beyond the violet. It may also be observed, that the rays effective in destroying a given tint, are in a great many cases, those whose union produces a color complementary to the tint destroyed, or, at least, one belonging to that class of colors to which such complementary tint may be preferred. For instance, yellows tending towards orange are destroyed with more energy by the blue rays; blues by the red, orange and yellow rays; purples and pinks by yellow and green rays. V. AMPHITYPE. This process is a discovery of Sir John Herschel and receives its name from the fact that both negative and positive photographs can be produced by one process. The positive pictures obtained by it have a perfect