i. 28 March 1844 - Strasbourg - Sending mosses of Swiss Alps, Tyrol and Carinthia. Is to visit Norway and Sweden. Publications. Drummond's and Gardner's mosses.
ii. 29 May 1844? - Strasbourg - (Addressed to R.J. Shuttleworth.) Announcement of Stirpes normales Bryologiae europaeae. Algae from Switzerland, etc.
iii. 29 November 1844 - Strasbourg - Sending copies of his Stirpes. Publications. Mosses from Norway and Sweden. (W.P. notes sum due from Schimper.).
iv. 14 June 1856 - Strasbourg - Publications.
v. 18 September 1856 - Strasbourg - Publications.