C tyo ] 



XL! I T . Proceedings of Learned Sock- ties. 



ROYAL SOCIETY. 



JVIarch 2.— The reading of Mr. Home's paper .on the in- 

 tervertible joint discovered in the basking sh;trk, was con- 

 cluded. Mr. Brando analysed the liquor found In this pe- 

 culiar joint, when it proved to be almost entirely animal 

 mucus or mucilage, without either gluten or albumen. 



March 9 — 16. — Earl of Morton, vice-president, in the 

 chair. A verv lone; memoir was read on the nature and mo- 

 difications of coloured concentric rings, exhibited in glasses 

 brought into contact, by Dr. Herschel. It is impossible to 

 give any adequate idea of the numerous and diversified ex- 

 periments performed by this indefatigable philosopher, whose 

 narrative of them is divided into above 60 subdivisions. 

 From these experiments it appeared that no coloured rings 

 were produced if the glasses were of the same quality, uni- 

 formly level, and brought perfectly into contact. Sir Isaac 

 Newton's opinion respecting *' fits of transmission" was 

 explained on his own principles of the known difference of 

 refrangibilitv of coloured rays. Various other optical phe- 

 nomena, relating to coloured rays, chromatics, and refrac- 

 tion, were incidentally illustrated. 



March Z-2. — Earl of Morton in the chair. An account of 

 experiments on Brazilian platina, by Dr. Wollaston, was 

 read. The very small specimen of platina from the silver 

 mines in Brazil, which Dr. W. analysed, was given to him 

 by the chevalier de Souza, the Portuguese minister in this 

 country.' Vauquelin having found platina, but no palladium, 

 in the silver mines of Guadalcanal, it was thence supposed 

 that this metal was peculiar to the Peruvian platina. The 

 Brazilian platina, however, has some external characters 

 different from that of Peru ; it is brighter, flat, not rounded 

 off at the corners, and has not that worn aspect which the 

 Peruvian platina presents. It also contains a small quantity 

 of gold, which was not found in the platina of Estrema- 

 dura. But notwithstanding the smallness of the speci- 

 men, native palladium was discernible in it by its external 

 characters : although white, like the platina, it exhibited flat 



square, 



