56 Anniversary Meeting. [Nov. 30, 



For more than forty years von Mueller has been working, without 

 intermission, at scientific botany and its practical illustrations. As a 

 botanical traveller and collector, he has, to quote the words of Sir 

 Joseph Hooker, " personally explored more of the Australian conti- 

 nent than any other botanist, except Allan Cunningham." No one 

 has investigated the Australian flora and the geographical distribu- 

 tion of its components with so much perseverance and success, and 

 no one has enriched our herbaria, laboratories, and gardens with 

 materials for study to so great an extent. The eleven volumes of the 

 1 Fragmenta Phytographiee Australia ' contain the descriptions of a 

 great series of new plants, and the unrestricted communication of his 

 collections and observations to the late Mr. Bentham rendered 

 possible the preparation of the ' Flora Australiensis,' in seven volumes, 

 the only account of the vegetation of any large continental area which 

 has at present been completed. 



He has especially demoted himself to the elucidation of the most 

 difficult, though most characteristic groups of the Australian flora ; 

 and as a result of his labours in this direction, his ' Eucalyptographia ' 

 may be more particularly mentioned, a work which will always be 

 the standard of nomenclature for the intricate genus Eucalyptus. Of 

 a similar character are his descriptions and illustrations of the 

 ' Myoporineous Plants of Australia,' and his ' Iconography of the 

 Genus Acacia.' To him is also due the foundation of the Govern- 

 ment Herbarium at Melbourne, the first great botanical collection 

 formed in the southern hemisphere, and the future centre of all 

 scientific work on the A.ustralasian flora. 



A Royal Medal has been awarded to Professor Osborne Reynolds 

 for his investigations in mathematical and experimental physics, and 

 on the application of scientific theory to engineering. 



Professor Reynolds was among the first to refer the repulsion 

 exhibited in that remarkable instrument of Mr. Crookes's, the radio- 

 meter, to a change in the molecular impact of the rarefied gas 

 consequent upon the slight change of temperature of the movable 

 body due to the radiation incident upon it ; and in an important 

 paper published in the ' Philosophical Transactions ' for 1879, he 

 deduced from theoretical considerations the conclusion that similar 

 phenomena might be expected to be observed in bodies surrounded by 

 a gas of comparatively large density, provided their surfaces were 

 very small. He verified this anticipation by producing on silk fibres, 

 surrounded by hydrogen at the atmospheric pressure, impulsions 

 similar to those which in a high vacuum affect the relatively large 

 disks of the radiometer. 



In an important paper published in the ' Philosophical Transactions ' 

 for 1883, he has given an account of an investigation, both theoretical 

 and experimental, of the circumstances which determine whether the 



