384? Intelligence and Miscellaneous Articles. 



•ft 



COLLECTING AIR FOR ANALYSIS. 



M. Gualtier de Claubry has successfully employed a strong solution 

 of sulphate of magnesia instead of mercury, for collecting air under 

 those circumstances in which it is requisite to invert a bottle containing 

 a fluid in the air intended for examination.— Ann. de Cliim. vol. xxxvii. 



CHLORIDE OF SODIUM AND SILVER. 



When chloride of silver is boiled in a strong solution of common salt, 

 a compound of the two chlorides is produced, which crystallizes as the 

 fluid cools. These crystals are not affected by light, and are decom- 

 posed by water j the solvent powers of the chloride of sodium over the 

 chloride of silver may be usefully employed in analysis. Similar com- 

 pounds may be obtained by using the chlorides of potassium or cal- 

 cium. — Institution Journal. 



OBSERVATIONS ON AMBER. BY M. BERZELIUS. 



It is well known that amber is most commonly found in brown coal, 

 and that it has been observed in the trunk of a tree lying in a mass 

 of brown coal. There is no doubt whatever of this fossil resin having 

 been originally a vegetable product. The numerous bodies found in- 

 closed in it, as for example spiders, wings of all sorts of insects, a co^ 

 rollap erfectly blown, (contaied in the collection of the Upsal Academy,) 

 impressions of barks and branches, which are not uncommon, suffi- 

 ciently prove that amber, like common resin, originally flowed in the 

 state of a balsam, and that it afterwards hardened under the form of 

 a resin. The following observations, if it were needful, would furnish 

 additional proof of the origin of amber. 



This resin contains at least five different substances : 1st, an odo- 

 riferous oil in small quantity : 2nd, a yellow resin intimately com- 

 bined with this oil, and which readily dissolves in alcohol, aether, and 

 the alkalies ; which is very fusible, and resembles common resins not 

 of fossil origin : 3rd, a resin difficultly soluble in cold alcohol, better 

 in boiling alcohol, from which it separates on cooling in the form of a 

 white powder, and which dissolves in aether and the alkalies. These two 

 resins and the volatile oil, which aether extracts from amber, form after 

 the evaporation of the aether upon water a natural viscous balsam, of 

 a strong smell and a bright yellow colour, which subsequently hardens, 

 preserving a portion of its odour. There is every reason to suppose 

 that this body is precisely what amber originally was, but still perhaps 

 less rich in essential oil'than then j and that the insoluble parts of 

 amber have been formed by time from the alteration of this balsam, a 

 portion of which has been enveloped and defended from further alte- 

 ration. The fourth substance contained in amber is succinic acid, 

 which is dissolved with the balsam by aether. The fifth substance is 

 insoluble in alcohol, aether, and the alkalies, and bears some relation 

 to the matter which John has found in gum-lac, and which he has de- 

 signated by the name of principle of lac (lackstoff) ; this is formed in 

 the greatest quantity when this resin is dissolved by an alkali, and 

 bleached by chlorine and precipitated. — Annates de Chimie,xxxxu\.2\ 9. 



INFLUENCE 



