200 Proceedings of the Wernerian Society. 



Sitta europcca ; the last differing, however, in being of a deeper co- 

 lour below. A fourth species was produced very nearly allied to 

 the Sitta Europesa, which, however, presented characters sufficiently 

 marked to form a new species ; and from the banded tail being the 

 most prominent, the Professor gave to it the specific name of 

 Vitticauda. A specimen of the Sitta frontalis from Northern India, 

 was also exhibited, and its wide geographic distribution pointed out, 

 it being first found in Java, and described by Dr Horsfield. 



3. It was mentioned, that the very remarkable fact of the -ex- 

 pansion of liquefied carbonic acid, lately observed by the French 

 academicians, has been fully verified by Mr Kemp, lecturer on 

 chemistry, who finds that the expansion is not peculiar to this li- 

 quefied gas, but belongs to all other gases in the liquid state. 

 At this meeting of the Society, Mr Kemp exhibited a specimen of 

 the liquefied sulphurous acid gas, hermetically sealed in a glass tube, 

 and separated from the materials from which it had been generated. 

 This specimen of the liquefied gas occupied 8 inches of a tube, 

 5~8ths of an inch in internal diameter, and when cooled from the 

 temperature of 60° down to 14° of Fahr., or the point at which it 

 becomes liquid under the ordinary pressure of the atmosphere, it 

 contracted one inch, but when heated an equal number of degrees 

 above 60°, viz. 46°, it expanded through a greater distance than it 

 had before contracted by the abstraction of an equal amount of 

 caloric, shewing that the expansion went on at higher temperatures 

 in a slightly increasing ratio, so that the expansion between its li- 

 quefying point, viz. 14° and 212°, the boiling point of w^ater, is 

 nearly one-third of its whole volume, the pressure against the ex- 

 pansion being at 212°, about 25 atmospheres. That this property 

 does not belong to the liquefied gases exclusively, but resides equal- 

 ly in all other fluids, when raised above their boiling points, is 

 shown by the following experiment ; thus, ether, when raised from 

 the temperature of 60° to 95° of Fahr., or its boiling point, under- 

 goes an inconsiderable expansion compared with the expansion pro- 

 duced by an equal increase of temperature above its boiling point, 

 when it: may be said to be in the same condition with the liquefied 

 gases in regard to pressure, and carbonic acid suffers nearly an 

 equal expansion by an equal increasing temperature with the lique- 

 fied gases. 



At this meeting Robert James Hay Cunningham, Esq. was 

 elected a Resident Member, and Dr Martin Barry a Non-resident 

 Member, of the Society. 



