THE LEYDEN JAE. 623 



where the upper edge of the coating is to be. The upper portion 

 being kept firm, by placing the thumb of the left hand outside upon 

 the jar and opposite to it the first and second fingers inside upon the 

 tinfoil, so as to prevent its being again displaced, the lower part is 

 fixed by applying pressure from above downwards. Small jars will 

 only allow of the forefinger being placed inside. The free use of 

 the right hand for the operation of pressing and rubbing will only 

 be possible in very large jars ; usually a small stick of wood of the 

 size of a pencil will have to be used, to the end of which a small piece 

 of linen or cotton stuff is tied with thread so as to form a roundish plug. 

 "When the strip is fixed well to the side of the jar, the last portion is 

 pressed upon the bottom, being careful to rub and press at first gently, 

 or the upper portion of the strip might be torn off again ; after a little 

 while greater pressure may be used. When the first strip is fixed 

 a second is introduced and attached in the same manner, but, 

 to prevent paste being squeezed underneath the first strip, pres- 

 sure and rubbing should only be applied downwards, not from 

 side to side. The second strip should overlap the first 3 or 4 mm 

 along the side, and its upper edge must be carefully placed in the 

 same horizontal line. The other strips are proceeded with in like 

 manner until the inner coating for the sides is complete. A circular 

 disc of tinfoil, being about 5 or 10 mm narrower than the vessel, is 

 then fixed to the bottom. It is necessary to make an incision in the 

 disc from the edge to the middle, so that the disc may better adapt 

 itself to the form of the bottom ; the cut edges may overlap one 

 another afterwards. The outer coating is attached in the same 

 manner. The paste should be neatly removed where visible with a 

 moist rag, the whole carefully dried, and the free portions of the 

 glass covered with shellac varnish. The glass should be heated 

 cautiously for the varnishing, as the upper portion of the tinfoil 

 when it gets too hot is apt to blister. 



The rod is fixed in small jars by means of a bung cork ; for larger 

 jars a disc of thick pasteboard may be used. The cork or the paste- 

 board disc should fit very tight into the neck of the jar, and the hole 

 in the middle for receiving the metal rod should only be just large 

 enough for the purpose. The cork or disc is pushed from below 

 upwards to near the knob, the elastic strip of brass is then fastened 

 to the rod, and pressing the brass spring a little together, that it 

 may pass through the neck, the rod is made to touch the bottom of 

 the jar, and the cork pushed down and pressed into the neck so that 

 the top of it is flush with the rim of the jar. Cork or disc is 

 further secured with sealing-wax, by placing first a thin layer all 

 round and then cautiously melting it uniformly with the blowpipe, 



