1809.] 



President's Address. 



Ill 



A Royal Medal has been awarded to Dr. Augustus Matthiessen, F.R.S., 

 for his researches on the electrical and other physical properties of metals 

 and their alloys. 



The earlier of Dr. Matthiessen's published researches related to the 

 preparation of the metals of the alkaline earths. Having succeeded in 

 establishing or perfecting methods for the production of these, he pro- 

 ceeded to institute a far more complete examination of their physical 

 properties than had previously been attempted. These researches appear 

 to have led to bis investigation of the more important physical properties 

 of the principal metals and their alloys. In some of these investigations 

 Dr. Matthiessen associated himself with younger workers in science of 

 proved ability, Messrs. Holzmann, Box, and Vogt ; and the results arrived 

 at were included in a series of nine papers published in the * Philosophical 

 Transactions.' They embrace the determinations of the specific gravities, 

 the expansion due to heat, the thermo-electric properties, the electric con- 

 ducting-power, and the effects of temperature upon the electric conducting- 

 power. 



The laws deduced from the results of Dr. Matthiessen's electrical expe- 

 riments are now in constant use by telegraphic engineers. The causes of 

 the great variations observed in the electric conducting-power of com- 

 mercial copper were first elucidated by him, and an important report was 

 made by him on this subject in 1860 to the Committee appointed by 

 Government to inquire into the construction of Submarine Telegraph 

 Cables. His investigation of this subject has resulted in very great im- 

 provement of the conducting-power of the copper wire used in submarine 

 telegraphy. Closely connected with this branch of his researches are the 

 investigations which Dr. Matthiessen carried out for the Electrical- Standard 

 Committee of the British Association, of which he was one of the most 

 active members. The resistance-coils issued by that Committee, which 

 have been very generally adopted as standard instruments, are all con- 

 structed of an alloy of platinum and tin, which, after a long series of experi- 

 ments, Dr. Matthiessen recommended as specially fitted for that purpose. 



Under the auspices of the British Association, Dr. Matthiessen under- 

 took, a few years ago, the investigation of the chemical constitution of 

 cast iron, and of the influence exerted upon the physical properties of that 

 metal by the several other elements which generally occur in association 

 with it. With these objects in view he has laboured most perseveringly 

 in the preparation of iron in a chemically pure condition, and in quanti- 

 ties sufficient to admit of the attainment of thoroughly trustworthy results 

 in the study of the physical and chemical properties of the pure metal and 

 of its alloys. His researches in this direction have recently been crowned 

 with success ; and the method of producing pure iron, which he has elabo- 

 rated, promises to be fruitful in interesting and important results in the 

 hands of himself and the other chemists with whom he has been associated 

 in this inquiry. 



