330 . OG. Williams on Organic Substances. 
letting it fall on plumbic dioxyd in an apparatus which caused 
the evolved gas to pass into a solution of baric hydrate, them 
sult being a copious precipitation of baric carbonate, 
aving shown that acetic acid can be formed from carbonic — 
disulphid and the chlorids of carbon, and oxalic and formic 
acids from the oxyds of carbon, the speaker proceeded to indicate 
the modes in which complex bodies, hitherto obtained from an- 
imal and vegetable sources, can be built up from elemental car 
bon and hydrogen. . : 
f carbon can only be made to combine directly with hydro- 
gen, no matter how simple the resulting compound may be, it 
becomes possible to effect the synthesis of a vast number of the 
most characteristic substances found in animals and vegetables. 
This brilliant result has been accomplished through the 
agency of acetylene, a most remarkable hydrocarbon which was 
first noticed-by Edmund Davy as long ago as 1836. 
There are two methods by which acetylene can be formed 
from inorganic materials—one devised by Berthelot, and 
other by the speaker. The first consists in passing a stream 
hydrogen through a globe in which the voltaic are (from 70 
| 
80 cells of a Grove’s battery) is produced between carbon points 
At this tremendous temperature the carbon unites directly with 
the hydrogen. The experiment was made, and the productioa 
of acetylene shown, by the formation of a precipitate a $010 
tion of ammoniacal cuprous chlorid. , 
The speaker then showed, experimentally, that much mY 
quantities of acetylene can be formed by the decompositio® Y 
the induction spark of carbonic tetrachlorid in presence ° y 
drogen, in accordance with the equation:— 
2(CCl,) + 5H, = C,H, + 8(HC)). 
ut the most simple and ready means of preparing en 
was shown to be by drawing air through the flame of ow s 
glass spirit-lamp, by means of an aspirator. So readl'y 
acal cuprous chlorid to obtain evidence of the presence of 
lene in the flame. he experi hen ed pr 
few seconds the solution became thick with the suspen" 
cipitate, f ole 
The speaker had ascertained that all the homologne the 
fiant gas give acetylene in abundance when subject! 
induction spark. Amylene does it readily in accor” 
€ annexed equation: — 
