SELF-PACKING VULCANITE APPARATUS. 303 



into the syringe by a rather powerful screw (e e). 

 We will suppose, then, that the case which I 

 have in my hand is one which is intended to be 

 packed in this new way. The teeth may be ap- 

 plied as usual by soldering on the mineral teeth by 

 means of wax, to the wax model, as we have been 

 in the habit of doing. When the teeth are all in 

 their place, a small piece of tapered brass rod, or 

 what is quite as efficient, a piece of wax about 

 the size of a pencil, is fastened to some central 

 portion of the case, if it is an upper jaw towards 

 the back part of the roof of the mouth. After 

 adjusting the intermediate piece to its place, wires 

 are inserted through the two holes at the side of 

 the flask, and connected to the wax which forms 

 the model to be afterwards made into vulcanite. 

 I may pass this flask round to show the position 

 of the teeth. [The flask was here handed round.] 

 The two wires, you will see, are in contact with 

 the case. The second plaster is then poured into 

 the intermediate division of the flask, the per- 

 forated lid (g) adjusted to its place, the tapered 

 rod of brass or wax appearing through the orifice. 

 The flask is then held together by a clamp (e. Fig. 

 A), consisting of a bottom plate provided with 

 three . arms and screws ; these are adjusted to a 

 top plate (/), of such a form as to leave the orifice 

 in the lid free. 



This form of clamp retains the two plasters in 

 perfect apposition, and prevents any reasonable 



