Bromine: historical information
Bromine was not prepared in quantity until 1860 but compounds of bromine were of some considerable importance well before it was recognised as an element. Long ago an excretion from a particular kind of mussel was used to make a purple dye called "Tyrian purple". It is now known that a key compound in this process is an organobromine compund.
It seems that an undergraduate chemist called Carl Löwig studying at Heidelberg presented one of his lecturers, Leopold Gmelin, with a sample of bromine that he had made over the summer holidays. Löwig's exams interrupted his studies long enough to allow a report from Antoine-Jérôme Balard to take precedence in 1826.