I 



M. Fraunhofer on the Laws of Light, 101 



water the temperature can never be much above %\%^ F. 

 The oil in general, after going completely through this pro- 

 cess, seems to have nearly the same properties as it formerly 

 had, and burns in a lamp equally well ; but a portion of its 

 adipocirous contents is in general precipitated. 



Glasgow, X'^th April 1827- ^ 



Art. XXI. — J short account of the results of recent Experi- 

 ments upon the Laws of Lights and its Theory. * By M. 

 Le Chevalier Fraunhofer, Member of the Royal Bava- 

 rian Academy of Sciences at Munich. 



In a Treatise of mine, which was printed in the eighth volumfe 

 of the Memoirs of the Royal Bavaiian Academy of Sciences 

 last year, I published new experiments on the Inflection of 

 light, and on the phenomena which arise from the reciprocal 

 action of inflected rays on each other, together with the de- 

 velopement of the laws which may be deduced from these ex- 

 periments. 



Led by the inferences which I had drawn, I have since con- 

 tinued these experiments ; and the following is a notice of such 

 of the results which I obtained as are suited to a short paper, 

 assuming, however, that all that the above treatise contains 

 on this subject is understood, -f 



In observing the phenomenon which takes place when the 

 light is inflected through a single small aperture by means of 

 a telescope, coloured spectra are seen, which, in respect to the 

 order of colours, are similar to the Newtonian coloured rings ; 



• Read in the Mathematical and Physical class of the Academy, June 

 14, 1823. 



As the Editor of this Work has already translated and publish- 

 ed from the French of M. Shumacher and M. Pictet, the whole of 

 Fraunhofer's first Memoir on the Spectrum, and the principal part of his 

 second Memoir on the Modification of Light by Iriflection, he has been 

 anxious to put the English reader in possession of the present Memoir, 

 which he has had translated from the original German, which appeared in 

 Gilbert's Journal for 1823. — Ed. 



t The substance of this Treatise will be found in the article Optics in 

 the Edinburgh Encychpagdia, toI. xv. p. 556. 



