LIME MACHINE ORIGINALLY EMPLOYED. 141

To obviate these defects the sulphuretted hydro-gen and carbonic acid which are the cause of themmust be removed, and to effect this, no methodmore economical and efficacious, has as yet beendiscovered, than to bring the gas confined under apressure ecpial to a column of water, not lessthan eight or ten inches in height, into contact withquick-lime, diffused through water. Other meanshave been tried, but all of them have failed to besufficiently efficacious or economical on a largescal'e.

Lime Machine originally employed for thePurification of Coal Gas.

In the lime-machine, until lately in use, the gaswas made to pass in the apparatus, through passageswhich could not be guarded from being stopped upin the course of time by the concretion of a quantityof carbonate and hydro-sulphuret of lime, formedduring the purification of the gas, so that when thestoppage occurred, a prodigious pressure was pro-duced in the machine, in consequence of which, itwas either found impossible to keep the distillatory