Yellow Fever Vaccine: Slightly dull, light-orange colored, flaky or crustlike, desiccated mass.
Yohimbine Hydrochloride: White to yellow powder. Melts at about 295, with decomposition. Soluble in boiling water; slightly soluble in water and in alcohol.
Yttrium Chloride: Colorless, deliquescent crystals. Soluble in water and in alcohol.