Chlolesterol Used to Prevent Rickets. Evidence suggesting that ergosterol is not the only substance that can be given the power to prevent rickets by exposure to ultra-violet light was presented t o the Institute of Chemistty of the American Chemical Society recently by Mrs. Elizabeth M. Koch of the University of Chicago. A commercial cholesterol, a substance found in nerve tissue, egg yolks: and blood, was exposed t o ultra-violet light. I t acquired the power of preventing rickets to a high degree, proving about one-seventy-fifth as effective as ergosterol, which has a very high anti-rachitic potency. When the commercial product was purified its potency was not nearly so great, but heating the purified product in nitrogen under pressure raised the potency to its original degree.-Scienc~ Scmice
