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Reritfication of Ether. ■-^New Phenomena of Sound. 4j 



SCIENTIFIC NEirS JND ACCOUNT OF BOOKS. 

 RcSlification of Ether, 



NE principal object in the reftification of ether, is to deprive it of the fulphiireous acid ; 

 for which purpofe the addition of a re-agent is neceflary. It has been ufual to add an alltali. 

 Dize has found it much more advantageous to add a fubftance which might afford the requifite 

 quantity of oxygen to convert this into the fulphuric acid ; in which ftate it is not difpofed 

 to rife and come over. Various metallic oxydes were tried, among which the black oxyde of 

 manganefe proved the beft and the cheapeft. His procefs is as follows : 



The fulphureous acid contained in unreclified ether being neutralized with oxyde of manga- 

 nefe, the fluid is decanted into a pewter vefTel of the capacity of fifty ounces, which is placed 

 on a water bath. To this veflel a head and worm are adapted, the latter of. which pafles 

 through a refrigeratory conftantly fupplied with water in a ftream from below, which caufes 

 the heated water to flow ofF above. The diftillatiun is then performed by raifing the bath to a 

 temperature of 36° (113° Fahrenheit if the decimal thermometer be here meant). The rec- 

 tification by this treatment ufually requires a day to complete it. The flavaur of the ether is 

 of the bell kind, and the produft about one-fixth more than in the ufual method with retort and 

 receiver. Dize has pradlifed this method with fuccefs for three years. 



Journal de Phyfique-t j^r//, 1798. 



EffeUs of the Cafes in producing Sound through a Pipe, ' 



Professor Chladni, well known for his numerous difcoveries relating to the theory of 

 found, engaged profeflbr Jacquin, of Vienna, to make fome experiments on the properties of 

 the different gafes confidered as fonorous bodies, particularly thofe gafes which conftitute our 

 atmofphere, and ferve to produce vocal founds. A glafs bell was furnifhed with a metallic 

 cork cemented to a neck at the top ; and in the bore of this cock, within the glafs, a fmall flute 

 or pewter (etain) about fix inches in length was fixed. The glafs being then placed on the fliclf 

 of the pneumatic vefTel, and filled with any particular kind of gas, a bladder alfo filled with the 

 fame gas, and provided with a cock, was adapted to the external aperture of the cock belonging 

 to the bell-glafs. In this difpofition of the apparatus, the flute was made to found by gently 

 prefling the bladder. Comparative experiments were made with atmofpheric gas, oxygen, hy- 

 drogen, carbonic acid, and nitrous gas. The intenfity of the found did not vary ; but when 

 compared with that produced by atmofpheric air, the oxygen gas gave a found hJlf a tone 

 lower; azotic gas, prepared by different methods, conftantly gave a found half a tone 

 lower ; hydrogen gas gave nine or eleven tones higher ; carbonic acid gas one— third lower, 

 and nitrous gas alfo very nearly a third lower. A mixture of oxygen gas and azote, in the 

 proportions of the atmofpheric ^ir, afforded the tone of this lafl ; that is to fay, it was half a 

 tone higher than each of the component parts alone. When the two gafes were not uniformly 

 mixed, the found was abominably harfh. Chladni intends to give a fuller account of thefe in— 

 terefling experiments. 



Journal de Phyfiquey Fol, IF, N.S. p. ^^. 

 G 2 Contribution 



