During his stay in Berlin in 1764, Boswell lived in the house of Karl David Kircheisen, the president of the Berlin city council.
Johann Bartholomaeus Rogler
Rogler is best known for having published a number of revised editions of Christian Ludwig's German-English dictionary (first published in 1706).1
Life with Boswell:
Boswell dined with Rogler and Josias von Qualen in Leipzig on October 6, 1764. Boswell thought Rogler's dictionary a translation of Johnson's great dictionary, augmented with “three thousand words taken from others, so that he has amassed all the rubbish which Mr. Johnson was with so much judicious care kept out of his book”. He got it wrong, of course - Rogler's dictionary was a revised editions of Ludwig's German 1706 dictionary, augmented with words from Johnson's English dictionary.
Rogler suggested to Boswell, that he should write to the Danish scholar Monsieur (Børge?) Riisbrigh and the Bishop of Bergen, Erik Pontoppidan, in connection with his (Boswell's) planned Scots Dictionary. Boswell noted his intention to do so, but in all likelihood he never actually wrote to any of them. In any case, Pontoppidan died in December of that same year.
Note 1: An 1808 reissue of Rogler's 1790 edition is available here: Google Books