386 Misreliniieoiii Intelligence, 



fusing it with an equal weight of tin, an alloy was obtained, 

 which was fusible in boiling resin. Afterwards triturating this 

 alloy with pure caustic magnesia in a mortar, a powder was 

 obtained of a very fine purple colour. 



26. Fulminating Gold. — Count de Maistre also describes a ful- 

 minating gold obtained by pouring a small quantity of solution 

 of gold into red wine, (Bordeaux) ; a sediment formed which, 

 when dried, and placed on burning charcoal in an iron capsule, 

 exploded. 



27. Soda alum. — An alum, containing soda as its alkaline 

 base, has been sent to the Royal Institution, by Mr. Beatson, who 

 states that it is decomposed, when in solution, by cold, which 

 causes the separation of crystals of sulphate of soda. It is 

 decomposed also by salts of potassium, which separate from it 

 crystals of common alum. A hasty analysis of it, made in the 

 laboratory, gave, in 100 parts of this alum, 51.2 of water, 32.14 

 sulphuric acid, 10 alumina, and 6.32 of soda ; 



Or, Water 51.2 



Sulphate of alumine 26.1 



Bi-sulphate of soda 22.4 



99.7 

 This gives 2 proportionals of sulphate of alumine, 1 proportional 



of bi-sulphate of soda, and 28 proportionals nearly of water ; 



hence its composition seems to be very analogous to that 



of common alum, as ascertained by Mr. Phillips. 



It crystallizes in octoedra, which are generally very imperfect. 



(See Journal, page 363, Vol. VI.) M. F. 



28. On the conversion of Ligneous matter into Gum, Sugar, a 

 particular Acid, and Ulmin. — M. Braconnot's researches on these 

 substances are of extreme importance, from the relation they 

 have to the conversion and formation of the same principles by 

 natural processes. The following is a compressed account of 

 his Memoir, which has just reached this country. 



Whilst examining the action of sulphuric acid on wood, 20 

 grammes (308.9 gr.) of dried elm saw-dust were moistened 



