262 



NOTICES AND PROCEEDINGS OF SCIENTIFIC 

 SOCIETIES. 



EDINBURGH. 



Royal Society March 7, 1831. Dr Hope, V. P. in the chair. A 



paper was read by Dr Christison, containing an account of his analysis of 

 the suety matter obtained by boiling the seeds of the Laurus cinnamonum, or 

 cinnamon tree. This he found to consist of a great proportion of the 

 vegetable principle of cerine, got by Professor Jahn of Berlin from the 

 seeds of the Myrica cordifolia, but which that chemist had not succeeded in 

 freeing from impurities. Dr Christison having, by repeated ablutions with 

 alcohol, removed all foreign matters, was enabled to describe the properties 

 of pure cerine. The most interesting of these is its capability of saponifi- 

 cation with alkalies. Being led, by the knowledge of the fact that the same 

 chemical principles exist in the various species of one genus, to extend his 

 observations to other species of the genus Laurus, the professor succeeded 

 in obtaining from the berries of the Laurus nobilis, or common bay, a 

 principle exactly the same with that described above. In order to be able 

 to distinguish vegetable cerine from the principle of animal wax, with which 

 Jahn conceived it to be identical — a view not supported by Dr Christi son's 

 observations — the professor proposes to place before the word cerine the 

 generic name of the plant yielding it. Thus, lauro-cerine, &c. 



Dr Knox read an account of a case of supposed congenital opening in the 

 front of the human trachea, or windpipe. 



Mr Allan read an extract of a letter from his son, giving an account of 

 the changes going on in Vesuvius, particularly in a crater about 800 feet 

 deep — about the size of Arthur's Seat inverted — which was nearly filled up 

 by the matters projected from a partial eruption about the end of December 

 and beginning of January last. 



March 21. Professor Russell in the chair. A communication from Dr 

 Brewster was read, containing an account of a new analysis of white solar 

 light. He shewed that it consists of the three primary colours, red, yellow, 

 and blue ; and that the other colours, shewn by the prism, are also com- 

 pounds of these. A portion of white light cannot be decomposed at all. 



A paper was read from Arthur Trevelyan, Esq. on the vibration of heated 

 metallic rods, when placed in contact with cold masses of another metal ; a 

 notice of which had already been laid before the Society. Mr Trevelyan's 

 conclusions, as summed up at the end of this paper, are, 1. That, to produce 

 the effects, the metals must be of different kinds ; one hard, which must be 

 heated, the other soft, which must be cool. 2. That the difference of their 

 temperature must be considerable, though the exact degree is not determined. 

 3. That the surfaces must not be exactly smooth, or no vibration will take 

 place. 4. That the interposition of a piece of another metal, however 

 thin, stops the vibration. 5. That the contact of the air, though essential 

 to the formation of the sounds, is not necessary for the occurrence of the 

 vibration. 



Wernerian Society. — March 5. Professor Jameson in the chair. A 

 paper on Indian Hail-storms, communicated by Dr Turnbull Christie, was 

 read. The occurrence of hail storms had been supposed to be confined to 

 the more elevated parts of the Indian continent ; but Dr Christie found, 

 that even the peninsula of India was occasionally visited by them, and that 

 the hailstones were sometimes of a large size. 



