| RefNo | Title | Date |
| EC/1866/07 | Muller, Hugo: certificate of election to the Royal Society | |
| NLB/12/179 | Copy letter from Herbert Rix, to Professor Michael Foster, Secretary, Royal Society | 31 December 1895 |
| RR/8/61 | Referee's report by Hugo Muller, on a paper 'On the normal paraffins.—Part II' by Carl Schorlemmer | 6 July 1877 |
| NLB/2/154 | Copy letter from Herbert Rix, to Dr Hugo Muller [Royal Society] | 6 February 1888 |
| NLB/2/157 | Copy letter from Herbert Rix, to Professor Michael Foster [Royal Society] | 6 February 1888 |
| NLB/2/961 | Copy letter from Herbert Rix, to Dr Hugo Müller, Fellow of the Royal Society | 14 January 1889 |
| NLB/2/981 | Copy letter from Herbert Rix, to Dr Hugo Müller, Fellow of the Royal Society | 13 December 1888 |
| NLB/7/392 | Copy letter from Theodore E James, to Messrs Harrison & Sons | 6 February 1893 |
| NLB/4/632 | Copy letter from Herbert Rix, to Sir Henry Enfield Roscoe, Professor William Edward Ayrton, Charles Baron Clarke, William Henry Mahoney Christie, Dr Hugo Muller, Dr Armstrong, and Professor Joseph John Thomson. | 25 July 1890 |
| NLB/3/535 | Copy letter from Herbert Rix, to Dr Hugo Müller, Fellow of the Royal Society | 5 July 1889 |
| NLB/4/1170 | Copy letter from Herbert Rix, to Dr Hugo Muller, Fellow of the Royal Society | 3 February 1891 |
| NLB/5/227 | Copy letter from Herbert Rix, to Dr Hugo Müller, Fellow of the Royal Society | 17 April 1891 |
| NLB/5/218 | Copy letter from Herbert Rix, to Dr Archibald Geikie, Foreign Secretary of the Royal Society | 16 April 1891 |
| NLB/5/616 | Copy letter from Herbert Rix, to Dr Hugo Müller, Fellow of the Royal Society | 23 July 1891 |
| NLB/5/872 | Copy letter from Herbert Rix, to Dr Hugo Müller, Fellow of the Royal Society | 6 November 1891 |
| NLB/10/843 | Copy letter from Herbert Rix, to Dr Hugo Muller | 18 February 1895 |
| NLB/10/619 | Copy letter from Herbert Rix, to Dr Hugo Miller, Fellow of the Royal Society | 4 January 1895 |
| NLB/5/673 | Copy letter from Theodore E James to Dr Hugo Müller, Fellow of the Royal Society | 1 September 1891 |
| NLB/11/279 | Copy letter from Herbert Rix, to Dr Hugo Muller, Fellow of the Royal Society, Treasurer, Lawes Trust | 24 May 1895 |
| NLB/12/149 | Copy letter from Herbert Rix, to Dr Hugo Muller, Fellow of the Royal Society | 18 December 1895 |
| NLB/14/390 | Copy letter from Robert William Frederick Harrison, to Dr Hugo Muller, Fellow of the Royal Society | 3 March 1897 |
| NLB/17/749 | Copy letter from Robert William Frederick Harrison, to Herbert Rix | 15 December 1898 |
| NLB/20/619 | Copy letter from Robert William Frederick Harrison, to Dr Hugo Muller, Fellow of the Royal Society | 1 June 1900 |
| NLB/21/625 | Copy letter from Robert William Frederick Harrison, to Dr Hugo Muller, Fellow of the Royal Society | 19 December 1900 |
| NLB/24/380 | Copy letter from Robert William Frederick Harrison, to Dr Hugo Muller, Fellow of the Royal Society | 6 May 1902 |
| NLB/24/675 | Copy letter from Robert William Frederick Harrison, to Dr Hugo Muller, Fellow of the Royal Society | 16 June 1902 |
| NLB/26/550 | Copy letter from Robert William Frederick Harrison to, Dr Hugo Muller, Fellow of the Royal Society | 8 April 1903 |
| NLB/46/676 | Copy letter from Robert William Frederick Harrison, to Dr [Hugo] Muller, Fellow of the Royal Society | 15 October 1912 |
| RR/7/112 | Referee's report by Hugo Muller, on a paper 'On the meteorites of Shalka and Breitenbach' by Mervyn Herbert Nevil Story-Maskelyne | 11 June 1871 |
| RR/8/16 | Referee's report by William Thomson, 1st Baron Kelvin, on a paper 'Experimental researches on the electric discharge with the chloride of silver battery' by Warren de la Rue and Hugo Muller | 21 November 1877 |
| RR/8/204 | Referee's report by Hugo Muller, on a paper 'On the normal paraffins. —Part III' by Carl Schorlemmer | 6 December 1879 |
| RR/8/155 | Referee's report by William Thomson, Lord Kelvin, on a paper 'Experimental researches on the electric discharge with the chloride of silver battery' by Warren de la Rue and Hugo Müller | 29 November 1879 |
| RR/9/12 | Referee's report by Hugo Müller, on a paper 'Chemical theory of gunpowder' by Heinrich Debus | 24 April 1882 |
| RR/7/42 | Referee's report by Hugo Muller, on a paper 'On the mineral constituents of meteorites' by Nevil Story Maskelyne | 16 February 1870 |
| RR/9/136 | Referee's report by William Grylls Adams, on a paper 'Experimental researches on the electric discharge with the chloride of silver battery. Part IV' by Warren De La Rue and Hugo Müller | 5 July 1883 |
| RR/11/125 | Referee's report by Hugo Muller, on a paper 'Voltaic cells with fused electrolytes' by J Brown | 30 January 1892 |
| RR/8/94 | Referee's report by William Thomson, Lord Kelvin, on a paper 'Experimental researches on the electric discharge with the chloride of silver battery' by Warren de la Rue and Hugo Müller | 3 May 1878 |
| NLB/2/241 | Copy letter from Herbert Rix, to Dr Hugo Muller, Fellow of the Royal Society | 9 March 1888 |
| NLB/12/209 | Copy letter from Herbert Rix, to Dr Hugo Muller, Fellow of the Royal Society | 6 January 1896 |
| RR/10/186 | Referee's report by Hugo Muller, on a paper 'On the present position of the question of the sources of the nitrogen of vegetation, with some new results, and preliminary notice of new lines of investigation' by John Bennet Lawes and Joseph Henry Gilbert | 28 June 1888 |
| RR/8/272 | Referee's report by Hugo Muller, on a paper 'On the diastase of Kôji' by R W Atkinson | 15 May 1881 |
| NLB/8/1028 | Copy letter from Herbert Rix, to Dr Henry Woodward, Fellow of the Royal Society | 12 February 1894 |
| RR/8/15 | Referee's report by William Spottiswoode, on a paper 'Experimental researches on the electric discharge with the chloride of silver battery' by Warren de la Rue and Hugo Muller | 27 August 1877 |
| PT/60/3 | Paper, 'On the resin of Ficus rubiginosa, and a near homologue of benzylic alcohol' by Warren de la Rue and Hugo Müller | [1859] |
| AP/38/36 | Paper, 'Chemical examination of Burmese naphtha, or Rangoon tar' by Warren de la Rue and Hugo Muller | 1856 |
| RR/8/326 | Referee's report by Hugo Muller, on a paper 'On allotropic or active nitrogen and on the complete synthesis of ammonia' by George Stillingfleet Johnson | 11 December 1881 |
| PP/2/41 | Paper, 'On the electric discharge with the chloride of silver battery' by Warren De La Rue and Hugo Muller | 1882 |
| PP/7/16 | Paper, 'On the limited hydration of ammonium carbamate' by H J H [Henry John Horstman] Fenton | 1885 |
| RR/12/273 | Referee's report by Hugo Muller, on two papers 'Experimental researches on vegetable assimilation and respiration.—No. I. On a new method for investigating the carbonic acid exchanges of plants' and 'Experimental researches on vegetable assimilation and respiration.—No. II. On the paths of gaseous exchange between aerial leaves and the atmosphere' by Frederick Frost Blackman | 9 January 1895 |
| RR/4/65 | Referee's report by August Wilhelm von Hofmann, on a paper 'On the resin of ficus rubiginosa, and a new homologue of benzylic alcohol' by Warren De La Rue and Hugo Müller | 25 February 1860 |
| MC/17 | Volume 17 of miscellaneous correspondence regarding business matters, sent to the Royal Society | 1897-1899 |