1818.] Proceedings of Philosophical Societies. 381 



IX. Brownish Red, and Orange. 



Hyacinth. Var. of essonite. 

 Hyacinth. Var. of jargoon. 

 Vermeille. Yar. of garnet. 

 Tourmaline. 



X. Gems characterized by particular Plai/s of LiglU. 



Starstone ruby. -j 



Ditto sapphire. i v ** i 



t,-., . ll > V ar. or coiundum. 



Ditto topaz. f 



Oriental girasol. J 



Opal. 



Moonstone. Var. of felspar. 



Oriental aventurine. Var. of felspar. 



XI. Opaque Gems. 



Turquoise de la vielle roche. Sky blue, greenish blue. 



Ditto de la nouvelle roche. Deep blue, pale blue, greenish blue. 



Article XVII. 



Proceedings of Philosophical Societies. 



ROYAL SOCIETY. 



April 2 . — A paper, by Mr. Joseph Swan, was read, giving an 

 account of a new method of making anatomical preparations. 



On the same evening a paper, by Dr. John Davy, was read, 

 on the urinary organs and secretions of some of the amphibia. In 

 several species of serpents, which were examined by the author, 

 the kidneys were found of very considerable size, and of a long 

 and narrow form. Ducts proceeded from them to the ureters, 

 which last terminate in what appeared to be a distinct receptacle, 

 communicating with the rectum by a sphincter. A white matter 

 is deposited in the urinary passages, which is occasionally 

 expelled by a kind of extraordinary effort, and which consists of 

 uric acid. The urinary organs and secretions of lizards were 

 found to be nearly similar to those of serpents. The fluid 

 appears to contain no urea. 



April 9. — A very important paper, by Sir H. Davy, was read, 

 containing an account of a series of experiments on the combi- 

 nations of phosphorus with oxygen and chlorine. 



The author commences by noticing some late analyses of the 

 phosphoric compounds, which have been made by Professor 

 Berzelius and M. Dulong, which differ both from each other and 

 from Sir Humphry's former results. This circumstance induced 

 him to reconsider the subject, and especially to attempt to 



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