36 



METHOD OF PEOCEEDING IN 



glass bodkin, and the cell filled with. it. The cell should 

 be quite full, but not to overflowing. 



The specimen should be again examined, to see that 

 it has not been displaced in introducing the fluid. The 

 glass cover is now to be laid on, with great care and 

 steadiness, and adjusted perfectly square, to meet the 

 walls of the cell. The superabundant fluid which will 

 escape outside, should be absorbed and removed by a 

 camel's-hair brush, observing that you do not thus take 

 up too much liquid, or air will insinuate itself between 

 the glasses ; and this must be avoided. The glasses 

 should be then laid aside for a short time, to allow all 

 moisture to dry from the edges ; after which a camel's- 

 hair brush, charged with varnish, is to be drawn along 

 the same, encroaching about half a line on the cover, 

 and a line on the slide. This last process must be 

 repeated two or three times, allowing an interval of 

 four or five hours to elapse between each application, 

 until a sufficient body of varnish is laid on, so that the 

 edges of the cover may be firmly and properly cemented 

 to the slide, and effectually prevent the evaporation of 

 the fluid. 



The mounted specimen must be left in a horizontal 

 position about twenty-four hours, when it may be laid aside 

 as finished : but as Japan varnish will take some time 

 before it gets properly dry and hard, care must be taken 

 that nothing rests against it until it is so. The edges 



