54 MOUNTING AND PREPARATION OF OBJECTS. 



CHAPTER IV. 



Mounting and Preparation of Objects, 



The present chapter might be considered superfluous 

 but for the fact that objects designed for Micro-pho- 

 tography require different treatment from those in- 

 tended for ordinary microscopic examiuation. In 

 addition to this it is right that those who have ob- 

 tained even a small amount of knowledge in practical 

 science should impart it to others, and thus prevent 

 the disappointment and loss of time, consequent on 

 a dearly bought experience. 



The usual method of mounting microscopic speci- 

 mens, is after preparing them by some of the ways 

 mentioned farther on, to place them on plate-glass- 

 slips three inches long and one wide, then after the 

 addition of a small quantity of a suitable preservative 

 medium, they are covered with a square or circle of 

 very thin glass, which is fastened in position either 

 by the medium itself, or by a ring of cement painted 

 round its edge. 



The disadvantages of this method will be apparent 

 when the advantages, of the one we advocate, are 

 stated. We never expect its universal adoption, 

 because the old plan gives greater scope for artistic 

 display, and the manufacture of a kind of article 

 whose external appearance is more likely to catch the 

 eye of the public. 



Our method is as follows. After the usual pre- 



