]ii Annual Report of the Council. 



1865 he described his " new form of spectrum microscope " and 

 the results registered thereby before the British Association. 

 Proceeding upon information published by Hoppe, and two 

 years later (1864) in greater detail by Prof. Stokes, Dr. Sorby 

 exhaustively examined the microspectroscopic properties of red 

 and brown cruorine and haematin, and from these figured no 

 less than seven characteristic absorption spectra, showing 

 incidentally that well-marked bands could be obtained from a 

 minute blood-stain when only one-thousandth part of a grain of 

 colouring matter was present. The importance of such mar- 

 vellously delicate analysis was at once obvious to medical men 

 and public analysis liable to be called upon to give evidence in 

 criminal cases. 



Dr. Sorby, the " Father of Petrography," was also destined 

 to become the Father of Metallography. His pioneer discoveries 

 in petrography led him to the sagacious conception that steel 

 itself might be a crystallised igneous rock ; and in February, 

 1864, he placed in the hands of metallurgists a new and most 

 valuable method of scientific mvestigation. 



On that date he read before the Sheffield Literary and 

 Philosophical Society, a paper " On a New Method of Illustrating 

 the Structure of Various Kinds of Blister Steel by Nature 

 Printing." In this paper he revealed the cellular structure of 

 hard blister steel. He then attempted to produce artificial 

 meteorites, but his efforts were not attended with success, 

 because, as is known now, his experimental conditions were 

 unsuitable. 



Dr. Sorby worked on iron and steel metallography during tlie 

 years 1863, 1864, and 1865, and, taking into consideration the 

 meagre chemical data then extant, his final theory, as to the 

 nature of steel seems almost of the order of inspiration. He 

 described crystals of nearly pure iron as consisting probably of 

 interfering cubes and octahedra, and after a lapse of nearly 

 forty-three years, the accuracy of his conclusions (with only 

 sectional planes to guide him) remains unshaken. In his " pearly 



