230 Analyses of Books. [Sept. 



The ulmin is precipitated by nitric, sulphuric, muriatic, phos- 

 phoric, oxalic, tartaric, and citric acids ; but not by distilled 

 vinegar. Ulmin thus precipitated is glossy, and has a resinous 

 appearance. Its colour is unaltered. It burns with flame, and 

 is reduced to white ashes. Alcohol and water dissolve it, but 

 only in very small quantity. Potash promotes its solution in 

 water; but neither ammonia nor carbonate of soda produce this 

 effect. English ulmin examined by Mr. Smithson exhibited 

 similar properties; but the quantity was too small to enable him 

 to acertain all the properties which I detailed in my paper. 



VII. On a Method of Freezing at a Distance. By William 

 Hyde Wollaston, M.D. Sec. R.S.] It is well known that the 

 temperature of liquids is cooled by evaporation; but in close 

 vessels evaporation is limited by the great bulk into which the 

 vapour expands. Dr. Wollaston in this paper describes an 

 ingenious contrivance of his, to which he has given the name 

 ofcryophorus, by means of which water may be frozen in close 

 vessels by its evaporation with great facility. This instrument 

 is a glass tube of this shape — 



Its internal diameter is about -i-th of an inch, each extremity is 

 blown into a ball, and the tube is bent at right angles about half 

 an inch from each ball. One of the balls is filled not quite half 

 iull of water. This liquid is boiled for some time to expel the 

 air, and the capillary tube at the extremity of the other ball is 

 then sealed hermetically. If the empty ball of this instrument 

 is plunged into a mixture of snow and salt, the- vapour within 

 it is condensed so fast that the water in the other ball freezes. 



VIII. A Catalogue of North Polar Distances of some of the 

 principal Fixed Stars. By John Pond, Esq. Astronomer Royal, 

 F.R.S.] This catalogue contains 44 stars, the distances of all 

 of which are determined within rather less than a second of ab- 

 solute precision. 



IX. A Description of the Solvent Glands and Gizzards of the 

 Ardea Arcrala, the Casuarius £;??//, and the Long-legged Casso- 

 wary, from New South Hales. By Sir Everard Home, Bart. 

 F.R.S] The ardea argala, a native of Bengal, feeding on 

 carrion, and very voracious, has its solvent glands disposed in 

 two circular masses, one on the anterior, the other on the poste- 

 rior side of the cardiac cavity. Each gland is made up of five or 



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