BIOCHEMICAL INVESTIGATION OF THE NITROGEN, WEIGHT AND WATER CONTENT OF CRYSTAL-LINE LENSES

Fifty or more years ago, Laptschinsky¹ and Cahn² analyzed both normal cattle lenses and cataractous human lenses for various chemical constituents. Among other observations they published comparative data on the protein content of the two kinds of lenses. According to Laptschinsky, the average figure for normal cattle lenses is 34.93 per cent, evidently computed on the basis of the fresh lens. Cahn, in reviewing the work of Laptschinsky and in discussing his own observations, stated that the normal cattle lens consists of about 94.71 per cent of protein, whereas cataractous human lenses show a protein content only of from 81.48 to 85.37 per cent, evidently computed on the basis of the dry lens substance. More recently, Jess³ stated that the cataractous lens is deficient chiefly in the crystallins, alpha and beta, as compared with the normal lens, and that the ratio of crystallins to albumins in