●●●●● ●●●● ●●0 Petrolatum(矿脂 ●●● ●●●● is a purified mixture of semisolid hydrocarbons obtained from petroleum It is an unctuous mass, varying in color from yellowish to light amber(琥珀色) ◆ It melts at temperatures between38°c and 60oc and may be used alone or in combination with other agents as an ointment base A commercial product is vaseline.Petrolatum （矿脂） is a purified mixture of semisolid hydrocarbons obtained from petroleum.  It is an unctuous mass, varying in color from yellowish to light amber（琥珀色）.  It melts at temperatures between 38C and 60 C and may be used alone or in combination with other agents as an ointment base.  A commercial product is Vaseline