The results obtained in a previously reported study1 of the effect of irradiation of cod liver oil showed that the antirachitic value of the oil is not enhanced by irradiation with ultraviolet rays from a quartz mercury lamp. In the preliminary study, the irradiated cod liver oil was fed to experimental animals for a period of ten days in amounts not exceeding 3 mg. Since it was felt that the amount of irradiated oil fed, or the length of the experimental period, or both, may have been insufficient, a second study has been made in which 15 mg. of an irradiated cod liver oil was fed to the experimental animals for a period of six weeks. A comment on this study, together with the results obtained, forms the basis of the present communication.
NATURE OF OIL
The oil used in the earlier test was not available for the present