Abstract
The protein of tobacco mosaic virus was extracted by phenol. After precipitation with methanol the sedimentation and diffusion constants were measured in alkaline solution. At pH 13,0 S20=2.0 and D20=9.6 was found. From these data a molecular weight of 18 800 ± 10% can be calculated, which corresponds to the size of the peptide subunit found by the endgroup determination.