THE METHODS OF MOUNTING MICROBES 93 



These fluids are used for mounting hardened 

 tissues, and they should be preserved in stoppered 

 or well-corked bottles ; while for daily use a small 

 drop-bottle of each fluid should be placed on a 

 table set apart for mounting purposes. It may be 

 mentioned that xylol balsam is the best mounting 

 fluid for stained microbes ; chloroform-turpentine 

 balsam acts well with hardened sections ; and benzol 

 balsam is the most useful solution for general micro- 

 scopic purposes. 



These mounting fluids are all used in the same 

 manner, therefore a description of mounting in 

 xylol balsam will also apply to the other fluids. 



The sections having been stained and washed, 

 they are placed for twelve minutes in absolute 

 alcohol contained in a watch-glass : the alcohol 

 dehydrates them. They are now drained, and then 

 placed in oil of cloves to clarify them. While in 

 this medium they should be carefully straightened 

 out with needles. 1 Having now placed a drop of 

 xylol balsam in the centre of the slide, it is spread 

 out with a needle ; then a section is carefully lifted 2 

 out of the oil of cloves, drained, and placed in the 

 xylol balsam. A small drop of xylol balsam is 

 placed on the under surface of a clean cover-glass, 

 which is lowered on to the section. With practice 

 and perseverance, slight pressure with the forefinger 

 is all that is required to produce a slide devoid of 



1 Ordinary steel needles mounted in wooden handles. 



2 A lifter is made by beating out one end of a copper wire, 

 and then turning up the broad portion. Lifters made of German 

 silver may be purchased at Messrs. F. E. Becker & Co., of 

 Hatton Garden, London. 



