adv. [f. prec.] By means of the spectroscope; in respect of spectroscopic qualities, etc.
1871. trans. Schellen’s Spectrum Anal., 16, note. When the light of burning magnesium is observed spectroscopically.
1879. Proctor, Pleas. Ways Sci., v. 125. The part of the remaining light spectroscopically most effective.
1903. Times, 25 March, 10/4. Radium … remains spectroscopically identical after many months of continuous emission of heat.
