You can use this work for any purpose, including commercial uses, without restriction under copyright law. You should also provide attribution to the original work, source and licence.
Creative Commons Attribution (CC BY 4.0) terms and conditions https://creativecommons.org/licenses/by/4.0
'Optics: a soap bubble exhibiting interference colours. Coloured mezzotint [?] by M. Rapine, n.d. [c. 1883] after B. Desgoffe.' by Blaise Alexandre Desgoffe. Credit: Wellcome Collection. CC BY