Asserts that a process for obtaining 'Turnbull's blue' recently published in PN was discovered and published in 1842 by JH. Adds a second case in which JH anticipated another author's result.

Notes introduction of 'Worthytype' process into commercial photography. Calls attention to process discovered by JH in 1832 for purifying uranium.

Describes a method created by JH [see JH's 'Lettre ... sur ... un nouveau procédé pour effectuer la purification complète de l'oxide d'urane,' Annales de chimie, 49 (1832), 306-11] for obtaining pure uranium.