what was the name of the specimen test that patient 61683 had received the first time until 09/2104?
select microbiologyevents.spec_type_desc from microbiologyevents where microbiologyevents.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 61683 ) and strftime('%y-%m',microbiologyevents.charttime) <= '2104-09' order by microbiologyevents.charttime asc limit 1