Letter from Karl Pearson, FRS, Biometric Laboratory, University College, London, to James Mackenzie Davidson Notes that he has got very good enamelled bromides of the X-ray negatives. Asks Mackenzie Davidson if he would care to have the transparencies or the negatives back as a reference of the interesting case. Offers to pay Mackenzie Davidson for the cost of the negatives. Notes he would like to show Mackenzie Davidson some radiographs made of another family, whose defect is even more interesting. 7 October 1907