Obituary. 161 



their wages, if the profits realised permit of this, it is provided 

 that a considerable portion of same be set aside for more general 

 interests. In the first place come grants for public institutions, 

 etc., for the benefit of Jena and district. Secondly, grants in aid of 

 research and teaching in the science of optics, which may take any 

 shape or form. Thirdly, grants in aid of pure scientific study or 

 research in the whole domain of science, and without reference to 

 any benefit it may confer on the " Stiftung." 



With what success Abbe has achieved his ideals is seen from 

 the mere fact that the " Stiftung " has already built a people's 

 institute, with a large public library, at a cost of 50,000/., and has 

 also subsidised the Jena University to the extent of close on 

 100,000/. 



Abbe had close relations with our Society, in which he took a 

 great interest, as is evinced by the fact that of the twenty-two 

 papers on the theory of the Microscope, which are published in the 

 first volume of his collected papers,* no less than nine are commu- 

 nications to this Society. A complete list of them is appended. 

 On 1st May, 1878, he was elected as an Honorary Fellow, and in 

 1879, when he came over to this country, he gave a demonstration 

 on his "Theory of the Microscope and the Nature of Microscopic 

 Vision " at one of our Meetings. A further series of his writings on 

 the Microscope, based on, as yet, unpublished material, may, we are 

 led to hope from Dr. Czapski's preface to Abbe's collected papers, 

 be forthcoming in another volume of these, and will certainly be 

 looked forward to with much interest. For, in the stress of con- 

 tinuous productive work, Abbe, unfortunately, never found time to 

 write for publication an exhaustive treatise on his " Theory of the 

 Microscope," or much of his other work, and it has to be gathered 

 out of various publications. With reference to the Microscope, his 

 collected papers to a great extent supply the want,f and Czapski's 

 " Outlines of the Theory of Optical Instruments after Abbe,"} as 

 well of a recently published work on " Image Formation in Optical 

 Instruments from the Standpoint of Geometrical Optics," § by the 

 scientific collaborators of the Zeiss Works, give much information 

 on a great deal of Abbe's other optical work and theories. The 



* " Gesammelte Abhandlungen von Ernst Abbe," by the scientific collaborators of 

 the Zeiss Optical Works, edited by Dr. S.Czapski, published 1904, Gustav Fischer, 

 Jena. 



t In chapter iii. of " Carpenter on the Microscope," edited by Dallinger, 8th 

 edition, 1901, will be found an excellent condensed account of the Abbe Theory, 

 with references also to certain modifications of Abbe's views. These latter must 

 have occurred about the year 1880. The best connected and condensed account of 

 the Abbe Theory in German will be found in Dippel's "Handbook of Microscopy," 

 2nd edition, 1882, chap. iii. 



% This work forms a part of Winkelmann's " Handbuch der Physik," but is pub- 

 lished separately. Second edition, 1904, published by Barth, Leipsic. 



§ Edited by M. von Rohr. Tublished 1904, Julius Springer. Berlin. 



