200 SECTION PHYSICS. 



from the necessity of vindicating his claims to certain important dis- 

 coveries, the originality of which have been contested by one who, 

 from the perusal of Matteucci's writings, was imbued with the impulse 

 to prosecute those researches upon which was afterwards founded his 

 own fame. This is the galvanometer which he used in his principal 

 experiments, and by means of which he discovered the muscular 

 current, in the year 1844. It was rewarded by your Society with the 

 Copley Medal. 



And under No. 1742^ of the Catalogue you will find another appa- 

 ratus sent by France, which Matteucci and Arago used in their 

 researches on the distribution of currents, inducted by magnetism in a 

 revolving disc of copper. 



I have the good fortune to be able to place before you the spectro- 

 scope made by Professor Donati, an astronomer of Arcetri ; and it 

 was by means of this instrument that in 1870, on the occasion of the 

 total eclipse of the sun, he observed the luminous lines of hydrogen. 

 In the last years of his too short career he constructed a new spectro- 

 scope for solar analysis, composed of twenty-five prisms, some of 

 which were placed in the very tubes which have the fissure and the 

 lenses of the telescope. 



Finally, allow me to place before you the galvanic chronographic in- 

 terrupter of Professor Felici, about which you have already heard 

 something in the conference held by my excellent colleague, Professor 

 Blaserna. 



Before ending, allow me to express my regret at Italy being so 

 inadequately represented at this great exhibition. A country in which, 

 little more than ten years ago, youth was prohibited from tasting of 

 the fountains of science or reading the works of the greatest of its 

 citizens of Dante, of Galileo such a country is too new to compre- 

 hend suddenly the high importance of scientific rivalry, of these 

 Olympiads of science. And yet it might have sent various objects 

 of Galvani, Volta's piles, Brugnatelli's gilding, the electro-magnetic 

 movers of Dal Negro, Melloni's apparatus, Belli's electrostatic in- 

 duction machine, and many other ancient and modern instruments, 

 to compete for the prize of merit with those of more fortunate nations. 



Florence alone, the birthplace of physical science, and which has 

 at all times cultivated it, has contributed largely with its treasures. 



