434 Obituary. 



conditions under which these visitants to our globe must have 

 been formed. 



The invention of the " Microspectroscope " was signalised by a 

 number of curious discoveries on the spectrum of the blood and the 

 changes that blood undergoes in time, of the colours of hah' in man 

 and the lower animals, the colours of eggs, of insects, and of the leaves 

 and flowers of plants, and their changes, of algas, fungi, and many- 

 other organic bodies. The absorption spectra of gems, and the 

 relations between absorption and fluorescence, were also studied by 

 Mm, and ingenious methods based on these observations were 

 devised for the analysis of organic substances and the detection of 

 poisons. 



In his later years, when he utilised his yacht for studies of 

 marine organisms and their distribution, and when much of his 

 time and attention was devoted to devising methods for preserving 

 these organisms and preparing them for exhibition as lantern 

 slides, we find him at all times utilising his Microscope in con- 

 nection with his interesting work. 



3. Sorby himself made the avowal that, throughout his career, 

 he was always more concerned to seek out new and fruitful lines 

 of research, than to pursue those already discovered to their 

 ultimate development. It might perhaps be expected that, con- 

 sidering his wide range of interests, and the facility with which he 

 abandoned old lines of investigation when attracted by new 

 problems, the outcome of his labours would be varied, curious, and 

 fascinating, rather than conducive to great advances in science or 

 productive of valuable commercial results. 



Nothing, however, could be further from the truth, for Sorby 

 will always be honoured as the pioneer in one of the most impor- 

 tant branches of geological science, and as the discoverer of a 

 method which is having a most potent influence on the develop- 

 ment of the industries of his native town. 



At the recent centenary of the Geological Society, the geologists 

 from every part of the globe united in hailing Sorby as the " Father 

 of Microscopical Petrography " — for his early work resulted in the 

 development of a method that has revolutionised the study of 

 rocks. A large and ever-increasing yearly output of literature 

 testifies to the importance which this branch of science has now 

 assumed. 



In the same way, the discoveries to which Sorby was led by 

 his study of the metallic meteorites, concerning the nature of the 

 compounds building up artificial irons and steels, have led to the 

 recognition of the " sorbitic " method as one of the most im- 

 portant aids in investigating the causes of the strength or weakness 

 of various products used in the industrial arts. And the use of the 

 method has now extended to other branches of metallurgy. 



Sorby's complete absorption in scientific labour and speculation 



