Abstract: | The absorption of ultra-violet light by three bacteriophages C13, C16 and C36, prepared with a strain of Escherichia communior has been determined. Each bacteriophage preparation showed a characteristic absorption curve, when the wave-length was plotted against the photographic density. Crude bacteriophage preparations absorbed more light than one such preparation obtained in a purer state, but the wavelength of maximum absorption remained the same. |