Sentence:  He was , however , fortunate in his <WSD>contact</WSD> with Prof. J. G. L. Manthey ( 1769 - 1842 ) , teacher of chemistry , who , in addition to his academic chair , was also proprietor of the `` Lion Pharmacy '' in Copenhagen where Oersted assisted him . 
Meaning of the word marked with <WSD> tags:  close interaction