Intelligence and Miscellaneous Articles, 237 



*<b 



lour is formed; when exposed to the air it exhales hydrochloric 

 acid. 



Nitric acid of middling strength dissolves hellenin without the 

 evolution of any hyponitrous acid, and water precipitates it unal- 

 tered ; when the mixture is heated the hellenin is converted into 

 what M. Gerhardt calls nitro -hellenin. 



Concentrated acetic acid dissolves hellenin ; the solution is colour- 

 less, and deposits by evaporation unaltered crystals of this substance ; 

 water precipitates the solution. 



Anhydrous phosphoric acid acts upon hellenin as it does upon 

 camphor, converting it into a carburetted hydrogen, which M. Ger- 

 hardt has named hellenene. 



Cold chlorine gas does not act upon hellenin, nor even when ex- 

 posed to the direct rays of the sun ; but when the mixture is heated, 

 hydrochloric acid is disengaged and a resinous body is formed, in 

 which a certain number of atoms of hydrogen are replaced by an 

 equal number of atoms of chlorine ; a drop of bromine produces with 

 hellenin an effervescence of hydrobromic acid ; the product is of a 

 yellow red, dissolves in alcohol, and is precipitated from it by water. 

 It is probably a compound analogous to that formed with chlorine, 

 and the author terms it hydrochlorate of chlorehellenin. 



Bichloride of tin and protochloride of antimony, the latter in 

 a state of fusion, eolour hellenin of a deep red colour, exactly like 

 concentrated sulphuric acid. 



When distilled with lime, hellenin yields a yellow inflammable 

 liquid ; it is neutral, does not mix with water, and in smell resembles 

 acetone. 



The analysis of hellenin performed by M. Gerhardt agrees nearly 

 with that of M. Dumas, and he considers it as constituted of 



30 atoms of carbon 1146*6 77'92 



20 atoms of hydrogen. . 124*8 8*41 



2 atoms of oxygen . . 200*0 13*67 



1471*4 100 



In composition it more nearly approaches creasote than any other 

 substance, which, according to Ettling, contains 



Carbon 77*42 



Hydrogen ...... 8*12 



Oxygen 14*46—100 



Ann. de Chim. et de Phys., t. lxxii. 



CHEMICAL AND CONTACT THEORIES OF VOLTAIC ELECTRICITY. 



After giving an extract from Professor Faraday's Sixteenth Series 

 of Researches, of which an abstract appeared in Lond. and Edinb. 

 Phil. Mag., vol. xii. p. 122, M. de la Rive remarks, "The question 

 of which Mr. Faraday treats in the memoir from which the fore- 

 going extract is given, is the subject of a warm controversy at the 

 present time, especially in Germany, where the partizans of the 

 voltaic theory of contact are numerous. The authority of Mr. 

 Faraday, and the clear and decisive manner in which he declares 

 himself in favour of the chemical theory, are of great weight ; the 



