Paper, 'On the demonstration of the presence of iron in chromatin by micro-chemical methods' by Archibald Byron Macallum Macallum writes: 'The investigation, some of the results of which are to he given in the present paper, was stimulated by the conclusions of studies which I carried on during the last five years, and by the observations of Bunge and Zaleski on the occurrence of iron-holding proteids in the food and in the liver.' Annotations in pencil and ink. Subject: Chemistry / Biology Received 23 April 1891. Read 30 April 1891. Communicated by Henry Newell Martin. A version of this paper was published in volume 50 of the Proceedings of the Royal Society as 'On the demonstration of the presence of iron in chromatin by micro-chemical methods'. 1891