536 



NATURE 



[January 22, 1920 



ever made. By 1851 he had become expert in 

 the new process, and was able to publish his 

 observations of the microscopic structure of lime- 



stones. In 1857 he presented to the Geological 

 Society his famous paper on the fluid inclusions 

 in quartz crystals, in which he ventured to draw 



-Magnification loo. 



Fig. 5. — Magnificalioii 5000. 



2 mm. Apochromat. Structure of fine lamellar and sorbitic pearlitc. The steel used in this 

 experiment had the following composition : C o"84, Si 0*30, Mn o'45, Cr I'la, Ni o"i2 per cent. 



conclusions as to the conditions 

 under which rocks had been 

 formed in Nature from the ex- 

 amination of the minute quan- 

 tities of liquid enclosed in the 

 microscopic cavities in crys- 

 tals. The paper was received 

 without enthusiasm, and even 

 with ridicule, so absurd did it 

 seem to study geolog^ical prob- 

 lems on the minute scale of 

 the microscope. Nevertheless, 

 Sorby's conclusions came to be 

 accepted by all geologists, and 

 his paper is now accepted as one 

 of the classics of the science. 

 In 1863 he turned his attention 

 to iron and steel, being led to 

 their study by an examination 

 of meteorites. Just as he had 

 fused masses of silicates arti- 

 ficially in an attempt to solve 

 some of the problems con- 

 nected with igneous rocks, so 

 he proposed to use the in- 

 formation to be derived from 

 .irtificial masses of iron and 

 steel for the explanation of the 

 characteristics of meteoric 

 irons. He exhibited sections 

 of iron and steel, and photo- 

 graphs taken from them, at 

 Sheffield and also at the Bath 

 meeting of the British Associa- 

 tion in 1864, and even these 

 early photographs, taken, of 



NO. 2621, VOL. 104] 



