Dr, T. Thomson on Pyroxylic Spirit and its Comjwtmds. 95 



Liebig's laboratory, examined and analyzed by Mr. Richard- 

 son in 1837. It was obtained by passing liquid cyanic acid 

 into pyroxylic spirit. The cyanate of methylene was depo- 

 sited in the state of a white crystalline powder. 



Its characters and composition are stated by Mr. Richard- 

 son to be the same as those of cyanic .'Ether. It must then 

 be C^ H^ O + 2 (C^ Az O) + 3 (H O). 



M. Laurent has formed elaidate of methelyne, margarate 

 of methylene, and oleate of methylene, by processes similar 

 to what has already been described. For the characters of 

 these compounds I refer the reader to Laurent's paper*. 



Acid compounds of methylene. — The first of these formed by 

 Dumas and Peligot they have distinguished by the name of 

 sulphomethylic acid. It is obviously an acidulous salt, similar 

 to althionic acid in its composition. This acid, together with 

 tartromethylic and racemomethylic, the only ones hitherto 

 examined, have been described in a preceding chapter of this 

 volume. 



Sidphamethylane. — When a current of dry ammoniacal gas 

 is passed through pure sulphate of methylene, the liquid be- 

 comes very hot, and is gradually converted into a soft cry- 

 stalline mass, which is probably a mixture of sulphate of 

 methylene and sidphamethylane. To obtain this last compound 

 it is merely necessary to treat sulphate of methylene with 

 liquid ammonia. When the two liquids are agitated together 

 a violent action takes place, and the sulphate of methylene 

 disappears. 



The liquid which remains after the reaction, being eva- 

 porated /« vacuo, yields crystals of sulphamethylane, in large 

 and beautiful plates. It is so deliquescent that it is difficult 

 to preserve these crystals. 



The analysis is difficult, but Dumas and Peligot think it 

 probable that it is composed of 



1 atom anhydrous sulphate of ammonia 

 1 atom anhydrous sulphate of methylene. 



Oxamcthylane. When a current of ammoniacal gas is 

 passed through oxalate of methylene, a slight heat is evolved, 

 but to produce the proper reaction, the oxalate of methylene 

 must be kept in a state of fusion. The liquid gradually be- 

 comes solid, and becomes at last a white crystalline matter. 

 When dissolved in boiling alcohol and allowed to cool, it 

 crystallizes in cubes with pearly faces. 



The constituents of this substance, according to the ana- 

 lysis of Dumas and Peligot, are 



* Ann, de Cheni. el de Phi/s., Ixv, ^Q. 



