288 Dr. Butlerow on Bioxymethylene. 



he was unable to obtain free methyloglycol, and in a recent series 

 of experiments* he has also been unsuccessful. When this sub- 

 stance is treated by potash, lime, ammonia, or even with water, 

 decomposition takes place with formation of the acetate ; but in 

 all cases the methylene group is also decomposed, and probably 

 with the formation of an acid. 



The decomposition of acetate of methyloglycol by means of 

 oxide of lead is peculiar, and leads to the formation of a new 

 body, which Butlerow names dioxy methylene. Its formation 

 may be thus expressed : — 



2( .rS'J n2N2 To") +4PbO = 4C^ H^ PbO^ + C^ H^ O^. 



V, (^V^ n U J J / Acetate of lead. Dioxymethylene. 



Acetate of methyloglycol. 



It is also obtained by the action of iodide of methylene on oxa- 

 late of silver. When a mixture in equal equivalents of these 

 substances is carefully heated under rock-oil, a decomposition 

 takes place ; a gas consisting of carbonic oxide and carbonic acid 

 is evolved, and a solid volatile substance sublimes with the vapours 

 of rock-oil, and condenses as a thin white crust on the receiver. 

 It is purified by being pressed between blotting-paper, and by 

 being successively washed with ether, alcohol, and water; it is 

 then dried and sublimed. It has the appearance of transparent, 

 hard crusts, with indistinct crystalline texture ; when heated it 

 has a peculiar, acute and ii'ritating odour. It is neutral, and 

 without taste. It volatilizes below 100° C, and at about 152° 

 it fuses and begins to boil. It does not readily dissolve either 

 in boiling alcohol, ether, or water. 



Its analysis led to the formula C"* H'* 0*, which was confirmed 

 by a determination of the vapour-density. 



The reaction according to which it is formed is as follows : — 



2C^'*^^J04) + 2C2H2p=C4H40''-F4AgI-f2C204-i-3C202. 



^ ^.\. ' Iodide of Dloxyme- 



Oxalate of silver, methylene, thylene. 



In its formation the elements of oxalic acid play no part, 

 except apparently to modify the action. Under certain circum- 

 stances, iodide of methylene, treated with oxide of silver, yields 

 dioxymethylene. 



When dioxymethylene is treated with iodide of phosphorus, 

 some iodide of methylene is formed. It is acted upon by oxi- 

 dizing agents with formation of carbonic acid and water. 



Dioxymethylene is isomeric with acetic acid, and contains 

 twice the elements of oxide of methylene, C® H^ 0^, the ether of 

 methyloglycol. From its formula it might be that ether, had 



* Liebig's Annalen, August 1859. 



