APPARATUS FOR FREEZING AND DRYING VIRUS IN LARGE QUANTITIES UNDER UNIFORM CONDITIONS.

1. The apparatus described was designed for the desiccation under uniform conditions of large quantities of yellow fever virus in the frozen state. 2. Several hundred cubic centimeters of virus material, distributed in small containers, have been desiccated simultaneously to almost complete dryness and with no appreciable loss of infectivity. 3. Good keeping qualities of the virus activity are insured by sealing the containers either while evacuated or after filling with dry nitrogen.