[Responding to WT's 1826-2-7], JH thanks WT for materials sent, makes suggestions regarding WT's upcoming trip to Geneva, and asks WT to deliver a book to [Alfred] Gautier.

Accepts Smith's invitation to visit Norwich next year to examine Linnaeus' herbarium. Is about to visit the Ionion Islands to study the local flora, intends to take Smith's "Prodomus Florae Graecae" and asks for any other recommendations. Asks if there is any particular family or genus of plants to look out for. Collected many duplicates on his last tour of Italy, Switzerland, Germany, Austria, and Carinthia, including a 'Lilium pumilum' exactly resembling the figure in Loddiges' "Botanical Cabinet" tab 358; and 'Fritillaria lutea' of Marschall von Bieberstein at an elevation of 5000 feet in alpine meadow of Col de Tende, only place hitherto observed in Europe. Currently has a collector in Sardinia.

Comments on Josef Fraunhofer's work on double stars, on quality and color of light from different sources, refraction of different kinds of light, and solution of a problem in conic sections. Is going to Geneva and Modena soon.