OF THE DESTEUCTIVE DISTILLATION OE BOGHEAD COAL. 
461 
-^-85 
-35 
opened, and mercury permitted to flow in until the globe is quite fllled. The rest of 
the process is continued as usual. Where several densities are to be determined in 
succession, this process saves more time than would readily be believed. 
The compression tap used in this experiment is capable of withstand- 
ing a very considerable pressure of mercury, and is so manageable that 
the smallest portion of metal may be added at will ; it is also particu- 
larly well adapted for various volumetric and gaseous operations. The 
following is the method of construction. A block of wood, a, c, d, 
has a square hole mortised in it, through which passes the vulcanized 
tube, e, /, k, attached at e, f to the lower orifice of the burette. A 
piece of hard wood, z, k, also passes through the mortise, and is retained 
in its place by the flange i. It is evident that on tummg the head of 
the screw, I, the piece i will be pressed against the vulcanized tube 
and collapse it. 
In order to facilitate comparison of the indifierent hydrocarbons 
from Boghead naphtha with the radicals, I annex the following Table, 
containing their boiling-points and densities in the fluid and gaseous 
state, according to various observers. 
k. 
Comparative Table of the Physical Properties of the Radicals. 
Boiling-Points. 
Densities. 
V apour-densities. 
Radicals. 
Q 
Z 
< 
.-I 
z 
< 
Pi 
Kolbe. 
N 
H 
Pi 
d 
Brazier and 
Gosslbth. 
C. G. 
Williams. 
Frankland, 
at 11 °. 
Wo* 
W 00 
w ^ 
o « 
WURTZ, 
at 0 °. 
C. G. 
Williams, 
at 18 °. 
Frankland. 
Kolbe. 
N 
H 
Pi 
p 
C. G. 
Williams. 
Theory. 
Propyle 
Q12 fJH 
Mean. 
68 ° 
0-6745 
2-96 
2-97 
Butyle 
C16 H18 
108° 
106 ° 
... 
119° 
0-6940 
0-7057 
0-6945 
... 
4-053 
4-07 
3-88 
3-94 
Amyle 
020^22 
155° 
158° 
159° 
0-7704 
0-7413 
0-7365 
4-899 
... 
4-956 
4-93 
4-91 
Caproyle 
C24H*'= 
... 
202 ° 
202 ° 
202 ° 
... 
0-7574 
0-7568 
... 
... 
5-983 
5-83 
5-87 
