AA&ElectricalandPhilosophicalApparatus — EuharmonicOrgan. 



iug experiments might be made on the refraction of light through 

 media of different densities. 



Besides glass and water and atmospheric air, the rays of light 

 migJit be directed throngh vessels of varied sizes and shapes, filled 

 with alcohol, ether, naphtha, or even the various gaseous sub- 

 stances, from the heavy carbonic acid gas to the lightest hy- 

 drogen. 



In these experiments the rays of light might also he examined 

 vhen separated into their different colours, and thus directed 

 through these various media. 



Perhaps these hints may induce some of your correspondents, 

 who have the leisure and the conveniencies requisite for the per- 

 formance of such experiments, to engage their attesition to them, 

 and commuriicale the result to the public. As to myself, I can 

 only say — Fuvgar vice Cot is. A Correspov.deut. 



*^* Experiments of the kind suggested by our correspondent 

 have been made, and have even been carried so far that the re- 

 sults were attempted to be applied some years ago to the im- 

 provement of achrouuitic telescopes by a gentleman in Edin- 

 burgh, though we have not heard with what success. As, how- 

 eJjer, his suggestion may induce o^her experimentalists to turn 

 their attention to the subject, we have given his well-meant com- 

 munication a place jn our pages, 



E[>ECTRICAL AND PHlLOSOPHir^L APPARATUS. 



The excellent collection of electrical apparatus and other 

 philosophical instruments, which have been employed by Mr. 

 Singer in his Lectures, is to be offered to public sale early In 

 the present season, in consequence of the discontinuance of 

 those lectures from the illness of Mr. Singer. 



LARGE EUHARMONIC ORGAN. 



Messrs. Flight and Robson of St. Martin's Lane have com- 

 pleted a large and fine Organ, for the East Indies, v.Ith com- 

 pound stops, the first of such which have yet i)ccn made, on tlie 

 Rev. Henry Liston's patent plan; in which instrument separate 

 pipes are provided for every sound (near (JO in each oc'.ave) in all 

 the upper parts of the scale, and skaders tor producing two or 

 three sounds (differing by comma major) from the same pipe, are 

 only used in some of the larger ranges of pipes, both for saving of 

 room, and because it has been found by experience, that in such 

 lower parts of the scale, the shaders act the i)e5t. In a s!iort time 

 Mr. Liston proposes to commence a Course of Lectures on the 

 musical scale, as now in use by singers, violinists, &c., illustrated 

 by experiments on all the chojds in use, and by performances, on 

 this large organ. ' expedi- 



