432 Obituary. 



A glance at the titles of more than two hundred and fifty- 

 papers published by Sorby will show how wide were his sympathies 

 and how varied his scientific tastes. Scarcely any branch of 

 physical or natural science escaped his attention, and he not un- 

 frequently strayed into the domains of archaeology, history, and 

 art. Yet amid all this bewildering range of pursuits, one fact 

 stands out conspicuously — his faith in and reliance upon the 

 Microscope as a most potent aid in scientific research. 



Sorby's contributions to microscopy may be classed under 

 three heads : — 1. Improvements in and additions to the Micro- 

 scope, designed to increase its usefulness in scientific investiga- 

 tions. 2. Discoveries, often of the most curious and unexpected 

 character, in relation to physics, natural history, and even to 

 medicine, sanitation, and jurisprudence, achieved by the use of the 

 Microscope. 3. The establishment of new methods of research by 

 microscopic means, which have had the most profound influence 

 on the progress of science and the improvement of technological 

 methods. 



1. Sorby's first work with the Microscope, commenced while he 

 was very young, was devoted to the study of the minute shells 

 from the Bridlington Crag. He tells us that he was pretty well 

 versed in the use of polarised light, and that he had practised the 

 art of drawing under the Microscope, and of representing objects 

 in their true colours. He soon found, however, that to do useful 

 work it was necessary, wherever possible, to obtain thin trans- 

 parent sections of the objects studied ; and having learned from 

 Professor William Crawford Williamson how anatomists and 

 botanists prepare thin sections of hard substances, it occurred to 

 him that it would be possible by the same methods to make trans- 

 parent sections of rocks. He at once set to work in this manner 

 and in time introduced many improvements in the method. In 

 employing such sections he was able to show that the polariscope, 

 attached to the Microscope, is no mere toy, but a most powerful 

 aid to scientific research. 



On the announcement in 1860 by Bunsen and Kirchoff of their 

 methods of spectrum analysis, Sorby at once directed his energies 

 to the employment of the Microscope in this interesting field of 

 research. Having devised a form of Microscope, with a spectro- 

 scopic attachment, he showed how in the most varied branches of 

 scientific work important results were to be obtained by the use of 

 the instrument. 



The study of stony meteorites and of their chondritic con- 

 stituents led Sorby in 1869 to employ the Microscope as an aid to 

 blowpipe-analysis, and thus to furnish valuable aid to the chemist 

 and mineralogist. By flattening blowpipe-beads while they were 

 still hot, and then examining them under the Microscope, he 

 showed that the characteristic crystals of various substances 



