552 
EXPLOSIVE CHARACTER OF OXIDE OF SILVER IN PILLS. 
n 
small cylinders of sheet metal with which the first is filled, and which is im¬ 
mersed in a strong solution of chloride of ammonium mixed with ammonia. 
The actual operation is performed by expelling the air from the entire apparatus 
by a stream of oxygen ; then, by applying heat to the carbonate of lead, the 
combustion-tube becomes filled with carbonic acid, and the copper turnings in 
front of the boat containing the substance can be heated without undergoing 
oxidation. The nitrogen which is produced during the combustion is swept by 
a stream of oxygen into the bottle containing the copper ; here the oxygen is 
absorbed from it, and the residual gas can be passed into a graduated tube and 
measured. Satisfactory analyses of several substances are recounted. 
The second communication describes— 
A Regulator of the Heat produced by means of Gas, for the use of 
Laboratories. —The apparatus will be readily intelligible from the accompanying 
drawing. The reservoir, which consists of a tube of any convenient form filled 
with mercury, is placed within 
the stove or other apparatus, 
the temperature of which is re¬ 
quired to be constant. It is 
connected with a, the other 
extremity of which, &, is closed 
by a sheet of thin caout¬ 
chouc bound over its extre¬ 
mity. At c is a vertical arm, 
ccl, to which is attached by a 
caoutchouc tube, a stop-cock, 
R, opening into a little bulb, e. 
A wide glass tube, fg, fixed 
upon ab by a cork, carries two 
tubes, the one, h k , sealed in 
at 7i, the other, m n, passing through a second cork. The extremity, m, ought to 
face the caoutchouc end, and be very near to it; mn is connected with the gas 
supply, and h k with the furnace or other apparatus of combustion. 
To put the apparatus into operation, the stop-cock R is opened ; the gas 
which comes by n m passes through the annular space existing between m and &, 
and away by hk to the burner. The mercury dilates, clears the stop-cock, and 
enters the bulb e. When a thermometer, introduced into the space to be 
heated, indicates a temperature close upon the desired degree, the stop-cock R 
is closed. The mercury can then dilate further only by inflating the caoutchouc 
end ; this takes the form of a hemisphere, and advances towards m n; the size 
of the annular space is then diminished, and thus the regulation of the gas is 
effected by the dilatation of the mercury. 
EXPLOSIVE CHARACTER OF OXIDE OF SILVER IN PILLS. 
Dr. Quain has forwarded to us for publication the following remarkable case, com¬ 
municated to him by Dr. Jackson, of Notting Hill, illustrating the great facility with 
which oxide of silver is reduced, and showing the necessity of caution in compounding 
pills containing that remedy :— 
Dr. Jackson writes :—“ May I tell you a curious fact with regard to the explosive 
nature of oxide of silver? The following prescription I gave to a lady last Monday,— 
Argenti Oxidi.gr.xlviij 
Morph. Muriat.gr.j 
Ext. Gentian. q. s. M. 
Make twenty-four small pills, and silver them, etc. 
