Ladenburg (Ann., 1875, 179, p. 163) to be symmetrical trimethyl benzene; terephthalic acid, the remaining isomer, must therefore be the para-compound.
The identity of the four valencies of the carbon atom follows from the fact that the heats of combustion of methane, ethane, propane, trimethyl methane, and tetramethyl methane, have a constant difference in the order given, viz.
By distilling an alloy of antimony and sodium with mythyl iodide, mixed with sand, trimethyl stibine, Sb(CH 3) 3 i is obtained; this combines with excess of methyl iodide to form tetramethyl stibonium iodide, Sb(CH 3) 4 1.
From this iodide the trimethyl stibine may be obtained by distillation with an alloy of potassium and antimony in a current of carbon dioxide.
On distilling trimethyl stibine with zinc methyl, antimony tetra-methyl and penta-methyl are formed.