254) Royal Society. 



Sulphuretted hydrogen solidified in masses of confused crystals of a 

 white colour, at a temperature of —122° Fahr. Euchlorine was 

 easily converted from the gaseous state into a solid crystalline body, 

 which, by a slight increase of temperature, melted into an orange- 

 red fluid. Nitrous oxide was obtained solid at the temperature of 

 the carbonic acid bath in vacuo, and then appeared as a beautifully 

 clear and colourless crystalline body. The author conceives that in 

 this state it might, in certain cases, be substituted with advantage 

 for carbonic acid in frigorific processes, for arriving at degrees of 

 cold far below those hitherto attained by the employment of the 

 latter substance. Ammonia was obtained in the state of solid white 

 crystals, and retained this form at a temperature of — 103°. 



The following liquids could not be made to freeze at —166°; 

 namely, chlorine, ether, alcohol, sulphuret of carbon, caoutchoucine, 

 camphine, and rectified oil of turpentine. 



The following gases showed no signs of liquefaction when cooled 

 by the carbonic acid bath, even when subjected to great pressure ; 

 namely, 



Hydrogen, Oxygen, at a pressure of ... , 27 atmospheres. 



Nitrogen and nitric oxide at a pressure of 50 atmospheres. 



Carbonic oxide at a pressure of 40 atmospheres. 



Coal-gas at a pressure of 32 atmospheres. 



January 23. — 1. "Observations de la Declinaison et Intensity 

 Horizontales Magnetiques observees a Milan pendant vingt-quatre 

 heures consecutives le 29 et30 de Decembre 184-4." Par M. Carlini. 



2. " Remarks having reference to the Earthquake felt in Deme- 

 rara on the morning of the 30th of August 1844." By Daniel Blair, 

 Esq., Colonial Surgeon of British Guiana. Communicated by the 

 Right Honourable Lord Stanley. 



The earthquake here described commenced at twenty-seven mi- 

 nutes past three o'clock, a.m. on the 30th of August, and continued 

 during two or three minutes. It appeared to be composed of two 

 waves or pulsations quickly succeeding each other, and producing 

 gyratory movements of the earth. Though the alarm it occasioned 

 was very great, no serious damage seems to have resulted from it. 



3. "An Account of the artificial formation of a Vegeto-alkali." 

 By George Fownes, Esq., Chemical Lecturer in the Medical School 

 of the Middlesex Hospital. Communicated by Thomas Graham, 

 Esq., F.R.S., Professor of Chemistry in University College. 



The substance which is the subject of investigation in this paper 

 is a volatile oil, obtained by distillation from a mixture of bran, sul- 

 phuric acid and water, and is designated by the author by the name 

 oi. furfurol. Its chemical composition is expressed by the formula 

 C'^'H'^O'^, and its properties are the following: — When free from 

 water and freshly rectified, it is nearly colourless ; but after a few 

 hours, it acquires a brownish tint, which eventually deepens almost 

 to blackness. When in contact with water, or when not properly 

 rendered anhydrous, it is less subject to change, and merely assumes 

 a yellow colour. Its odour resembles that of a mixture of bitter 

 almond oil and oil of cassia, but has less fragrance. Its specific 

 gravity at 60° Fahr. is M68 ; it boils at 323° Fahr., and distils at 



