Methylene. 
OXALATE OF METHYLENE. 
Distil a mixture of equal parts of sulphuric and oxalic acids 
and spirit of wood , a liquid passes, which, exposed for some 
time to the air deposits voluminous crystals which are oxa- 
late of methylene. This ether melts towards 51°, and distils 
at 161°. It crystallizes perfectly in rhomboidal plates of 
great brilliancy. Its formula is H 3 0,C 4 H 4 C 4 3 ; that is to say, 
one atom of oxalic acid, one atom of methylene, and one 
of water. 
ACETATE OF METHYLENE. 
This is obtained by the distillation of two parts of spirit of 
wood and one of crystallizable acetic acid. It is a colour- 
less liquid, of an agreeable odor, boiling at 55° C; its specific 
gravity is 0.919 ; its formula IPO, C 4 H 4 C 6 , H 6 3 . 
SULPHO-METHYLATE OF BARYTA. 
This is obtained by the same process as the sulpho-vinate 
of baryta, a salt with which it corresponds. It crystallizes 
in quadrangular plates, colourless and unalterable in the air. 
Its formula is C 4 H 4 , H 3 OS0 3 +H 4 3 . In treating the aqueous 
solution of this salt by a sufficient quantity of sulphuric acid 
to carry off the baryta, filtering and evaporating in vacuum, 
the bisulphate of methylene is obtained, which corresponds to 
the sulpo-vinic acid of alcohol ; it crystallizes very well. The 
results of all these experiments of M. M. Dumas & Peligot, 
present the following facts : 
1. Spirit of wood corresponds to alcohol. 
2. In losing half of its water, it forms a gaseous ether. 
3. Its radical unites volume to volume, with the hydracids, 
to form neutral anhydrous ethers. 
.4. It unites atom to atom with the oxacids to form salts, 
always hydrated. 
5. It forms with phosphoric and sulphuric acids, bisalts, 
which dissolve the mineral bases to form double salts. 
6. Finally chemistry is enriched with three new gases by 
