1835.] Pyroxylic Spirit and its Compounds, 376 



been brought in this country, is -812. Dumas, however, 

 states that its density at the temperature of 68° is '798, and 

 that of its vapour 1*120. Its boiling point, according to the 

 same authority, is 151°|,at a pressure of 30 inches. 



1 . Pyroxylic Spirit, or Hydrate of Carhydroyen. — For the 

 purpose of analysis, the pyroxylic spirit was rectified with 

 lime newly burned, and lastly distilled with mercury in a 

 retort supplied with a thermometer which indicated the 

 temperature 151°, from the beginning to the end of the 

 process. Its composition was found to be, carbon, 37*7; 

 hydrogen, 12*5 ; oxygen, 49- 8. This agrees very nearly, 

 taking into consideration the sp. gr., with 



1 vol carbon . . . = '4166 = 1 atom . . . -75 



2 vols, hydrogen . -1388 2 atoms . . -25 

 \ vol oxygen . . . '5555 1 atom ... 1* 



Mill 200 



Hence, this substance is a hydrate of carbydrogen, CH -f 

 HO. Dumas has, unnecessarily, coined a new name to 

 distinguish this base, viz. Methylene, (from ^Sv wine, and 

 v\y] wood). What advantage is gained by this innovation it is 

 difficult even to guess at. The disadvantages of designating 

 simple compounds by arbitrary names (since this compound 

 turns out to be one of the simplest organic compounds with 

 which we are acquainted) are sufficiently obvious, and we 

 trust that this name will not be adopted by British chemists. 

 The existence of this simple compound of hydrogen and 

 carbon in pyroxylic spirit was demonstrated in 1826 by Dr. 

 Thomson. (Edin. Trans, xi. 15. Inorganic Chemistry, i. 

 194, ii. 294.) It is difficult to allow ourselves to suspect 

 that Dumas should have been ignorant of this fact, which 

 has been published for nine years, but in consequence of 

 the absence of any allusion to it, it is impossible, in charity, 

 to avoid drawing such a conclusion. Dr. Thomson ob- 

 tained the compound of 1 atom carbon + 1 atom hydrogen 

 the basis of pyroxylic spirit, according to Dumas, by mixing 

 3 parts of muriatic acid, 1 part nitric acid, and 1 of pyroxylic 

 spirit, applying heat, and receiving the gas disengaged over 

 mercury. The product was, a mixture of a new inflammable 

 gas 29 parts, deutoxide of azote 63, azote 8. 



The new gas was composed of 1 vol. carbon, 1 vol. 



