70 Meetings of the Scientific Association of Great Britain. 
4 
the alkali of the glass; this remark would however not apply to 
glasses at Paris, which is far from the sea. 
Prof. Robinson recommends, that the present observatory shold 
be used for magnetic experiments, but this is objected to by Prof. 
Wallace,* because the rock} of the Calton Hillis highly magnetic. 
Sept. 12.—Life Apparatus.—Mr. Murray described an appara- 
tus for communicating between a stranded vessel and the shore ; with 
a method of illuminating, by might, the path of the arrow and the 
vessel ; this, if effectual, must be very important. 
Mode of Registering Meteoric Phenomena.—Mz. Adie, optician 
in Edinburgh, communicated a register of the weather, for ten years, 
in which the state of the thermometer and barometer was shown by 
undulating lines; the depth of the rain of each day by a broad red 
line; the thunder storms by a scarlet mark; the aurora by a blue 
one ; and a part of the space, allotted to each day, was tinted of a 
particular color, to represent the direction of the winds, so that the 
views of the weather, for the different years, had only to be com- 
pared together, and it would, immediately, be seen which of them 
had been remarkable for heat, rain, steadiness of weather, or the con- 
trary. , 
Expansion.—Mr. Adie, civil engineer, found by a pyrometer 
heated by steam, that when a rod of straight Sie well seasoned 
oak was kept dry, it expanded only about ;; of the rate of plati- 
num; black marble 4 as much as glass; sandstone of Craigleith 
Quarry, very nearly equal to cast iron. 
CHEMISTRY AND MINERALOGY. 
Chairman, Prof. C. Hope. 
Sept. 9—Atomic Weights.—Dr. Turner expressed the opinion 
maintained in the iBransdevions of the Roy. Soc. of London, that 
the atomic weights of bodies cannot be represented by whole num- 
bers. ‘This result would lead to great practical inconvenience, al- 
though we must follow truth wherever it may lead us. Without 
doubt the facts will be reviewed by others. 
Mercury.—Dr. Thomson believed that the mercury imported in- 
to Britain is pure. 
Sept. 10. —New facts in relation to Combustion.—Dr. Charles 
Williams shewed, that many organic substances exhibit, in a dark 
place, a pale lambent flame, like that of phosphorus just below ac- 
tive combustion; this happens, when vapors begin to be evolved ; 
Re 
* Inaseparate paper. See Jameson’s Journal, October, 1834. 
¢ Itisa porphyritic trap. 
