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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. Slightly soluble in water and in alcohol; soluble in boiling water.
Yttrium Chloride: Colorless, deliquescent crystals. Soluble in water and in alcohol.