Butylated Hydroxytoluene (BHT) used as antioxidant in various products most notably in vegetable frying oil. About 5% wt solution in isopropyl alcohol dropped onto slide and allowed to dry under coverslip 24 hrs.
Olympus BHS 10x Splan APO DIC using iphone 5s through eyepiece
BHT (antioxidant)
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