“…is obtained when a combination of selenium and mercuric oxide is,used as catalyst; this is due to the THE catalytic effect of small amounts of selenium, selenium oxychloride, selinites, or selenates in the oxidative digestion of nitrogenous organic matter by the Kjeldahl method is well known (5,13,17,20,28,32). A combination of mercuric oxide and selenium acts much more effectively than either of them singly in accelerating the decomposition of proteins (1,4, #3, 25, S3, So).…”