Referee's report by George Downing Liveing, on a paper 'Argon and its companions' by William Ramsay and Morris William Travers Sectional committee: Physics and chemistry Recommended for publication in Philosophical Transactions in full, and without modification, as it makes a distinct step in the advancement of knowledge. All the illustrations can easily be reproduced and this should be done. The subject matter of the paper has been investigated with great patience and careful labour and the results are of great interest. Some of the inferences are of a speculative character and the evidence does not convince him that they are correct. Nevertheless they are put forwards in a perfectly legitimate way and arise naturally from the discussion of the experimental results. [Published in Philosophical Transactions A, 1901]. Endorsed on verso as received 17 December 1900. 16 December 1900