METHODS OF CEMENTING CELLS. 



271 



about five inches square, it may very well be heated, either 

 upon the ring over a chemical argand lamp, or upon one of 

 the rings of a retort-stand, and a spirit lamp used. By far 

 the best plan is to have a piece of wrought iron about six 

 inches long, two and a half inches broad, and one-eighth 

 thick, with small legs to support it, about three inches from 



Kg. 173. 



the table ; the legs for convenience of carriage (as shown in 

 fig. 173) are jointed, and under the table a spirit lamp is placed 

 to heat it. 



Whilst the plate is being made warm, the cell and the 

 slide to which the cell is to be cemented, are to be laid 

 upon it, and on the sides of the cell small pieces of marine- 

 glue, cut either into lumps or shavings, are to be placed ; these 

 must be watched, and as soon as they begin to melt, they may 

 be moved one towards the other with a sharp-pointed instru- 

 ment, so as to cover the whole of the surface which is to be 

 cemented ; as soon as this is done, and the glue is seen to boil, 

 the cell may be taken up with a pair of forceps and turned over 

 upon the slide, and when it has been adjusted to its right place^ 

 it may then be firmly pressed down upon the slide with 

 a piece of flat wood, so that all the superfluous glue, with any 

 air bubbles that are present, may be squeezed out. The 

 cell may now be removed from the plate and placed upon a 

 piece of wood ; before it gets cold the superfluous glue may be 



