Page:Thruston speech upon the progress of medicine 1869.djvu/12

10 different physiological and pathological processes—for instance, in healthy and diseased respiration. We may hope for abundant results from such a research.

The spectroscope is a joint gift from both chemistry and physics: the mysterious dark lines of Wollaston or Fraunhofer's spectrum, which must be so familiar to many here, have been shown to be variously illuminated by incandescent chemical substances; and by the great genius of Kirchhoff and Bunsen they have been made to bear witness to the presence of these substances, when inconceivably small in quantity.

By a natural, but not the less wonderful sequence, they have enabled men to create a chemistry of the sun and of the stars, and have detected the presence of 15 of the mundane elements in the sun, and of 8 in the stars, nebulas and comets. They have even demonstrated the varying density of the photosphere of the sun, and have declared the composition of its rose-tinted flames.

The spectroscope has also watched the conflagration of a world whose parallax the astronomer could not measure, and has noted the degree and nature of its combustion, by the waxing or waning of its light. In hearing of such achievements as these, may we not say with Coleridge, "In wonder all philosophy begins, in wonder it ends, and admiration fills up the interspace"?

Whilst, however, some have thus been searching the universe, others have turned the same instrument, the spectroscope, towards the minutest recesses of the