On the Magnetic Influence of the Lunar Spectrum, 39 



found the same to be the case with cedar oil. The impure 

 solid oil begins to boil between 100° and 150°, water passes 

 over. The solid oil may then be distilled at 275°, the greater 

 portion passes over at 282° C. It may be still further purified 

 by crystallization from alcohol. It smells aromatic; melts at 

 74° C. ; little soluble in water ; formula C^^ H^^ O^. Density 

 of vapour 8"4; calculated 8*1 ; its composition may therefore 

 be represented by C^^ H"*^ + H"* O'^. By repeated distillations 

 with anhydrous phosphoric acid a yellowish oily fluid is ob- 

 tained, which smells like the solid oil; Walter calls it cedren. 

 Formula is C^^ H"***. Density of vapour 7*9, calculated 7'5. 

 Cedren boils at 248° C. By pressing the common cedar oil 

 a liquid oil may be obtained, which boils between 264° and 

 268° C. It has the same composition as cedren. Specific gra- 

 vity 0'98.—Annale'n de Chim. et de Phijs.^ Avril 1841, p. 498. 

 [To be continued.] 



VIII. On the Magnetic Influence of the Lunar Spectrum^ in re- 

 lation to a new Theory of Terrestrial Magnetism. 



To the Editors of the Philosophical Magazine and Journal. 

 Gentlemen, 

 T HAVE to request the favour of your insertion of the ac- 

 -*- companying paper " On the Magnetic Influence of the 

 Lunar Spectrum." I conceive it of sufficient importance to 

 attract the attention of natural philosophers at home and 

 abroad, and I trust that its perusal will, in accordance with 

 the author's wishes, induce further investigation of the pecu- 

 liar qualities of indirect, or reflected light, in relation to the 

 moon-beam, as distinct from the caloriflc qualities which ac- 

 company the direct light of the sun, as well as from the gra- 

 vitating power of the moon. 



It is clear that the establishment by multiplied experiments of 

 the assumed fact, that the light of the sun reflected from another 

 heavenly body, while unaccompanied by those heating, and 

 possibly, gravitating properties by which it is attended in the 

 solar beam, is capable of causing peculiar magnetic phasno- 

 mena on the earth's surface, must lead to a vast change in 

 the opinions at present entertained on the laws which control 

 the development of magnetic and electrical influences. 



So far as the author's experiments have been carried, they 

 appear, not only from his memoir, but also from his personal 

 explanations to myself, to have been conducted with care, 

 and to bear out to a great extent, his preconceived opinions ; 

 but in a question of such importance it becomes matter of 

 much anxiety to the originator of new views, to find that the 



