760 Transactions of the American Institute. 



Celestial Observations in the Southern Hemisphere, 

 The expedition sent out from England under Lieutenant Jolm 

 Herschel to observe, in Asia, the great eclipse on the 17th of August 

 next, have already done useful work. "With a spectroscope furnished 

 by the Royal Society, six nebula have been examined. The great 

 nebula in Arago presents a spectrum of bright lines, like those 

 exhibited by the great nebula of Orion, and is thus proved to be in 

 the gaseous state. 



Transformation of Organic Bodies into Hydro-Carbons. 



Prof Berthelot, of the College of France, has described a simple 

 process by which hydrogen may be substituted for all other elements 

 found in combination with carbon in organic bodies. The reagent 

 used by him is an aqueous solution of hyJriodic acid of density two. 

 The quantity of acid employed, always in excess, is greater in pro- 

 portion as the organic substance to be decomposed is deficient in 

 hydrogen. Both are heated in a sealed tube to 527 degrees Fahren- 

 heit fur ten hours. A series of changes take place, which result in 

 transferring the hydrogen in the acid to the carbon and forming 

 compounds generally homologous with marsh gas, or hydride of 

 ethyl. Alcohols, ethers, aldehydes, acids, aromatic carburets, alka- 

 loids, complex nitrogenized bodies, when heated, are broken up by 

 the superior saturating power of hydrogen, which, under these con- 

 ditions, displaces the strongest electro-negative elements. 



Brorsen's Comet. 



This comet, discovered in 1846, was missed at the perhelion pas- 

 sage in 1851. It was seen in 1857; again missed in 1S62, and redis- 

 covered in April, 1868. It must not be confounded Avith anotlier 

 bearing the same name and revolving in a more extended orbit. 

 The comet just discovered has been subjected to spectroscopic analy- 

 sis by Mr. Iluggins, of London. The spectrum consists of three 

 bright bands, resembling those seen in the spectrum of Donati's 

 comet. Their length proves that they are not due to the nucleus of 

 the comet alone, but are partly the result of the light of the coma. 

 It appears that the nucleus, and nearl}- the whole of the coma of this 

 «omet are self-luminous. 



New Process for Making Steel. 



An invention explained at a recent conversazione of the Insti- 

 lution of Civil Engineers, London, consists in grinding pig iron 



