284 Dr. Hare’s Improved Barometer Gage Eudiometer. 
course, in lieu of the five volumes introduced, two volumes of car- 
bonic acid, and one residual volume of oxygen will remain. 
By means of a forcing air pump, of which a description will be giv- 
en in the next number of this Journal, the gas may be transferred toa 
receiver, and washed with ammonia, or milk of lime, and then allowed 
again to enter the iron bottle. Meanwhile, by due attention to the 
gage, the quantity which has been absorbed may be ascertained ; and 
consequently, the proportion of carbonic acid resulting from the oxi- 
dizement of all the carbon in the gas subjected to analysis. 
Instead of employing the forcing air pump, by substituting a large 
valve cock for the screw by means of which an aperture in the bot- 
tle at A is closed, mercury may be introduced through a funnel, and, 
by its pressure, the residual gas may be easily conveyed, by a flexi- 
ble leaden tube, to a receiver over the mercurial reservoir, and ana- 
lyzed in the usual way: For this purpose it is necessary that the 
valve cocks with which the mercury comes in contact, should be of iron 
or steel ; and, accordingly, I employ such where mercury is to be used. 
2 gases may be supplied, without previous measurement and 
dina by receiving them into the bottle from their respective 
reservoirs, and measuring them as they enter, by means of the gage.* 
* Isubjoin an engraving of the colorimotor, by means of which the ignition of 
the platina wire, and consequent inflammation of the Bascous mixtures are ac- 
complished 
‘This engraving will convey an idea of the calorimotor suitable to effect the ig- 
nition of the platina wire in the galvano ignition apparatus above descr ibed. It 
