92 



A third skeleton, the most remarkable of all, is repre- 

 sented by Dr. Koch to have been the second found by him. 

 This specimen, which measured one hundred and twenty feet, 

 and had a very perfect head, was carried from this country 

 to Dresden, and afterwards exhibited in Breslau and Vienna. 



In connection with this subject, the President exhibited 

 Pontoppidan's figure of the Sea-serpent, and observed that 

 he believed in the existence of such an animal, that there 

 were many well-authenticated facts in favor of its existence, 

 and that very possibly the Zeuglodon and the Sea-serpent 

 are anatomically similar. 



Dr. C. T. Jackson communicated some chemical re- 

 searches, which he had recently made on the composition of 

 the scales of the Gar-pike. 



He slated that he had discovered fluorine as one of their com- 

 ponents, and had etched glass with the fluo-hydric acid, elimi- 

 nated from the ashes of the scales by the action of sulphuric 

 acid. The analysis was yet incomplete, but he would state that 

 the scales contain 45.2 per cent, of animal matter, destructible 

 by heat, and that the mineral matters consist of phosphate of 

 lime, fluoride of calcium, and phosphate of magnesia, with some 

 carbonate of lime. The proportion of lime, in 100 grains of the 

 ashes, was 45.1 per cent., and of magnesia 8.8 per cent., while 

 the phosphoric acid, already separated in this preliminary or 

 qualitative analysis, was 29.96 per cent. 



A complete analysis will soon be finished, and reported to this 

 Society. 



He remarked that the search for fluorine was suggested by an 

 idea communicated to him by Mr. C. Girard, that the scales of 

 fishes were "supposed to be anatomically homologous with the 

 enamel of teeth," an idea that now is sustained by chemical 

 analogy. 



Dr. J. B. S. Jackson exhibited the leaves and pods of the 



