diactinic, a. Optics.
(daɪækˈtɪnɪk)
[f. di-3 = dia-1 +Gr. ἀκτίν- a ray + -ic.]
Having the property of transmitting the actinic rays of light.
| 1867 W. A. Miller Elemen. Chem. i. (ed. 4) 230 Rock-salt, fluor-spar, water..are almost as diactinic..as quartz. 1880 19th Cent. Mar. 529 Substances which are chemically transparent are said to be diactinic. 1880 Athenæum 11 Dec. 781/3 Experiments which prove the diactinic character of substances constructed on an open chain of carbon compounds. |
So diˈactinism, ‘the condition of transparency for chemical or actinic rays’ (Syd. Soc. Lex. 1883).