&0 On Vegetable and Animal Analysis , 
We now exhibit to the class* an apparatus of the above 
description. It is formed of three distinct pieces : one is 
a very thick glass tube, closed at its lower extremity by 
the blow-pipe, and open at its upper end, about two deci- 
metres in length, and eight millimetres in breadth ; it has 
laterally, five centimetres from its aperture, a very small 
tube also of glass, which is soldered to it, and which re- 
sembles that which we should adapt to a retort for receiv- 
ing the gases. The other piece is a copper ferule into 
which we insert the open extremity of the large glass 
tube, and with which it is united by means of a mastic 
which melts only at forty degrees. The last piece is a 
peculiar kind of stopcock, in which the whole merit of 
the apparatus consists. The key of this stopcock has no 
hole through it, and turns in every direction without giv- 
ing vent to the air: there is simply about the middle of it 
a cavity capable of receiving a small pea : but this cavity 
is such that being in its upper position, it corresponds to 
a small vertical funnel which penetrates the socket, and 
of which it forms in some measure the extremity of the 
beak, and which when brought back to its lower position 
communicates with, and is a continuation of, the body of 
the stopcock, which is hollow, and is screwed to the ferule. 
Thus, when we put small fragments of any matter into 
the funnel and turn the key, the cavity is soon filled, and 
carries the matter into the body of the stopcock, from 
which it falls into the ferule, and from thence to the bot- 
tom of the glass tube. 
If this substance, therefore, be a mixture of hyper-oxy- 
genated muriate of potash and of vegetable substance in 
proper proportions, and if the lower part of the glass tube 
be sufficiently warm, it will briskly take fire : the vegeta- 
ble substance will then be instantaneously destroyed and 
transformed into water and carbonic acid, which will be 
® OF the National Institute. Editor. 
