70 Intelligence and Miscellaneous Articles. 



widely different from that usually given. The doctrine of an excess 

 of carbonic acid in the atmosphere, at the time when the coal was 

 deposited, being the cause of the very large quantity of carbon which 

 coal now contains, was alluded to ; but difficulties were said to attend 

 that hypothesis, which by many is considered to be more plausible 

 than correct. After the lecture the visitors adjourned to the mu- 

 seum of anatomy, where specimens were exhibited of the anatomical 

 structure of coal conifers, and of coal itself, seen under the micro- 

 scope, together with a spirited sketch by Mr. Hardy of the sup- 

 posed appearance of the vegetation of Newcastle at the period of 

 the coal deposit. 



ROYAL SOCIETY OF EDINBURGH. 

 Keith Prize. — At the meeting of the Society on Monday, Decem- 

 ber 2, this biennial prize, consisting of a gold medal and piece of 

 plate, was presented to Mr. Graham for his paper on the Diffusion 

 of Gases. 



XVI. Intelligence and Miscellaneous Articles. 



COMPOSITION OF OIL OF BITTER ALMONDS. 

 [Continued from vol. iii. p. 392.] 

 Bromide of r I "'HIS compound is prepared by mixing hydruret of 

 Benzoyle. — A benzoyle (oil of almonds,) with bromine. The mix- 

 ture becomes hot, and gives vapour of hydrobromic acid, which, as 

 well as the excess of bromine, is expelled by heat. This bromide 

 is a brownish semifluid crystalline mass at common temperatures: 

 a gentle heat reduces it to a yellowish brown liquid. Its smell re- 

 sembles that of the chloride, but it is much weaker, and slightly 

 aromatic. Exposed to the air it smokes a little, but when heated 

 intense vapours are given out. It is inflammable, and burns with a 

 600ty flame. 



It is slowly decomposed by water : when heated under water, it 

 remains there in the form of a brownish oil. By long boiling it is 

 converted into hydrobromic acid and crystallizable benzoic acid. It 

 dissolves readily in alcohol and aether without being decomposed, 

 and it may be separated by evaporation in the form of a crystalline 

 mass. 



Iodide of Benzoyle. — This does not appear to be obtainable by 

 direct action : it is readily procured by heating iodide of potassium 

 with chloride of benzoyle. It distils in the state of a brown liquid, 

 which on cooling becomes a crystalline mass of the same colour : 

 it then retains iodine in solution. When pure it is colourless, cry- 

 stallizes in tables, fuses readily, but each time it decomposes and 

 yields a little iodine. Its smell, action upon water and alcohol, and 

 combustibility resemble the preceding. 



Sulphur et of Benzoyle.— It is procured by distilling chloride of 

 benzoyle with well powdered sulphuret of lead. It has an oily ap- 

 pearance, and becomes a yellow soft crystalline mass. Its smell re- 

 sembles that of sulphur. It does not appear to decompose by boil- 



