OF THE DESTEUCTIVE DISTILLATION OF BOO-HEAD COAL. 
741 
was used, into the tubulature of which a large pipette was fastened by means of a cork. 
The neck of the retort was closed. The pipette being removed and the bromine com- 
pound introduced, some freshly-cut fragments of sodium were added. The pipette 
being returned to its place, the whole was allowed to remain until the action of the 
sodium, at first energetic, became sluggish in consequence of a coating of bromide 
covering the metal. Gentle heat was then applied, upon which the fluid entered into 
ebulhtion, but the vapours condensing in the pipette constantly returned to the retort. 
During the reaction the sodium acquired a superb blue colour, reminding us of the phe- 
nomena observed by M. Bouis when acting on chloride of capryle with the same metal. 
The addition of the sodium was continued until no more action occurred, upon which 
the pipette was removed and the fluid distilled over. To ensure absence of bromine, it 
was once more rectified over sodium, but the metal remained perfectly brilliant until 
the end of the operation. 
The fluid thus procimed was not the only product, for the bromide of potassium in 
the retort was mixed with greasy and carbonaceous matters. The hydrocarbon sub- 
mitted to a fractional distillation, came over at 71°, instead of 116°, as would have been 
the case if the bromine had reacted mth sodium in an analogous manner to iodized 
propylene. The following are the analyses of this fluid : — 
I. T677 gramme yielded -5251 of carbonic acid and •2164 water. 
II, -1703 gramme yielded -5354 carbonic acid and ’2178 water. 
Experiment. 
r \ 
Mean. 
Theory C"H“. 
Carbon . 
. . 85-4 
85-7 
85-6 
85-7 
Hydrogen 
. . 14-3 
14-2 
14-3 
14-3 
100-0 
The bromine compound is therefore decomposed by sodium in a manner totally different 
to iodide of allyle. To determine the value of w, I determined the density of the vapour 
of the fluid. The operation was performed in an apparatus permitting the experiment 
to be made at any desired pressure. It was originally intended to ascertain the density 
at several pressures ; the experiment was consequently commenced with an extra column 
of 205‘5 millimetres of mercmy, the atmospheric pressure being 759-2. The elastic 
force of the vapour was therefore equal to a column of mercury 964-7 millimetres in 
height. On consideration, the idea of making more than one experiment with the 
vapour of this hydrocarbon was abandoned until its formation had been repeated several 
times. 
Corrections made. 
Weight of substance -4240 grm. 
Volume of vapour 116-5 cub, cent. 
Atmospheric pressure 759-2 mm. 
Extra pressure 205-5 mm. 
Temperature of vapour . . . . . 98°-0 
Density 3-02 
