1813.] 



Scientific Intelligence. 



221 



X. Freezing of AIcqJioI. 

 Mr. Hutton, of Edinburgh^ by a new method, ivhich he has 

 not thought proper to make known, but which he conceives 

 capable of producing an unhmited degree of cold, has succeeded 

 in freezing alcohol of the specific gravity of 0*798, and even of 

 a specific about as low as 0*790 at the temperature of GG°. The 

 alcohol he conceives froze at the temperature of -- 1 iO° ; but no 

 stress can be laid upon any such determination, as the contrac- 

 tion of the alcohol at the instant of freezing is probably irregu- 

 lar. It divided into three layers. The uppermost, yehow, 

 consisted probably of the oils to which spirit owe their flavour, 

 and which could not be removed by the concentration. The 

 lowermost was the alcohol, probably still retaining water. This 

 is nearly a tasteless liquid, acco'-ding to Mr. Hutton : what the 

 middle stratum is, he does not mention. This discovery of Mr. 

 Hutton is of moment, as it removes the only anomaly that 

 existed against the general law, that all liquids become solid when 

 exposed to a sufficient degree of cold. 



Article X. 



Proceedings of Philosophical Societies, 



ROYAL SOCIETY. 



On Thursday the 28th January a paper by Dr. Brewster was 

 read, On some New Properties of Light. This paper contained 

 a kind of abstract of the author's numerous and interesting 

 experiments on light. It was divided into four parts. 1 . On a 

 new property of light discovered in the agate. In a plate of 

 transparent agate about -^th of an inch thick, cut in a direction 

 perpendicular to the laminse, besides the colourless image of the 

 object seen through this siibstance, there was another image 

 strongly coloured. On viewing this coloured image through a 

 prism of Iceland crystral, it was found to possess the propei ties of 

 doubly refracted light, disappearing at the quadrants when the 

 prism was turned round. The colourless image possesses the 

 same property. When a ray of light passes obliquely through a 

 thin plate of agate, if it be received upon another plate of agate 

 cut parallel to its coats, it easily passes through ; but if the plate 

 be cut in a direction perpendicular to the coats, it is totally 

 reflected. Carnelian and chalcedony, which are kindred sub- 

 stances, possess analogous properties. Besides the tw^o images 

 above-mentioned, there is a nebulous appearance always visible 

 in agate, probably occasioned by its want of complete transpa- 



