claim: Doxycycline may cause blue to change color.
evidence: Ammonium sulfide , also known as diammonium sulfide , is an unstable salt with the formula -LRB- NH4 -RRB- 2S .. Aqueous solutions purporting to contain this salt are commercially available .. With a pKa exceeding 15 , the hydrosulfide ion can not be deprotonated to an appreciable amount by ammonia .. ammonia. ammonia. hydrosulfide. hydrosulfide. deprotonated. Deprotonation. Thus , such solutions mainly consist of a mixture of ammonia and -LRB- NH4 -RRB- SH .. ammonia. ammonia. Ammonium sulfide solutions are used occasionally in photographic developing , to apply patina to bronze , and in textile manufacturing .. photographic developing. photographic developing. patina. patina. bronze. bronze. textile. textile. Also , due to its offensive smell , it is the active ingredient in a variety of foul pranks including the common stink bomb .. stink bomb. stink bomb. It can be used as a selective reducing agent -LRB- cf Clonitazene -RRB- , where there are 2 nitro groups only one of them is selectively reduced .. Clonitazene. Clonitazene