84 
ME. a. GOEE ON THE PEOPEETIES OP LIQUID CAEBONIC ACID. 
A small quantity or fragment of the solid substance to be subjected to the action of 
the liquid acid was placed securely in this tube, the sides of the plug welted with a 
saturated solution of paraffin in chloroform, and the stopper strongly forced while 
slippery into the mouth of the tube, taking care not to jerk or force any of the sulphuric- 
acid into contact with the alkaline carbonate. The plug was then fastened down tightly 
by means of the two transverse binding wires, each of which was composed of a twisted 
strand of four “No. 30” copper wires. It is important that a plug of the exact 
diameter be carefully selected. 
For convenience of manipulation, the tube was placed 
in the hole of a transversely perforated cork ; the cork 
fitted rather loosely in a short piece of brass tube ; the 
tube fixed upon a wooden peg, as shown in figure 4, in 
which I is the hole, J the cork, K the brass tube, and 
L the wooden peg with a prolongation of less diameter. 
The cork could thus be readily turned upon its axis, 
and the glass tube placed and retained in various 
positions. 
As a protection from accidents by explosion, and for further convenience of manipula- 
tion, a moveable cage or box was constructed for each tube ; its sides, top, and bottom 
were made of wood, and its front and back were of fine iron wire-gauze ; its dimensions 
were 12 inches high, 12 inches wide, and 5 inches from front to back ; the pieces of 
gauze were nailed to the wood on one of their vertical edges only, so that they served 
the purpose of doors. A small vertical strip or piece of wood was fixed at the back part 
of the box, with a hole at its middle part to receive tightly the small projecting part 
of the horizontal peg L, fig. 4. An inspection of fig. 5 will 
make more clear the whole arrangement. 
The tube, charged with its acid and carbonate, is placed 
in the frame in the position shown by the lines M, N, O in 
fig. 5 ; and the operator having previously protected his 
hands by thick leather gloves, his eyes by a pair of spec- 
tacles, and keeping the wire-gauze door between his face 
and the tube, occasionally turns the supporting cork upon 
its axis in the direction of the arrow, so as to cause a little 
of the acid to flow upon the alkaline carbonate ; this must 
be done mth cautious watching and in very small quan- 
tities at the commencement, otherwise the bubbles of gas which ascend through the oil 
of vitriol will carry some of the latter acid into contact with the contents of the little 
glass cup. The process requires much watching ; and if at any time the chemical action 
is allowed to progress too rapidly, the generating tube is liable to burst in consequence 
of the heat evolved. 
Ihe tube is thus occasionally turned until after the lapse of several hours it has 
Eig. 5. 
