METHOD OF MOUNTING OBJECTS IN ELUID. 283 



CHAPTEE VI. 



METHOD OF MOUNTING OBJECTS IN FLUID. 



All very delicate animal and vegetable tissues, to exhibit 

 their structure clearly, should not be mounted in the dry way 

 or in Canada balsam, but in some preservative fluid, such as 

 spirit and water, Goadby's solution, or one or other of the 

 fluids which have already been enumerated. 



The most minute structures, such as the vessels of plants, 

 the muscular and other tissues of animals, requiring in aU 

 cases exceedingly high powers for their due exhibition, must 

 of necessity be preserved in very thin cells, with a small 

 amount of fluid. 



The best method is as follows : — Take a slip of thin plate 

 glass, of the size adopted by the Microscopical Society, viz., 

 three inches long by one broad, or any other convenient size, 

 and after having cleaned it thoroughly by washing with a 

 dilute solution of caustic potash, to remove all grease, let it 

 be laid flat, and a drop of one or other of the preservative 

 fluids presently to be enumerated placed upon it ; in this the 

 object is laid, and after having been properly spread out with 

 the needle point, it is ready to receive its cover of thin 

 glass. This cover should be selected with care, and be as 

 thin and flat as possible; when freed from all grease by 

 being rubbed with caustic potash, it should be wiped with 

 a clean cloth or chamois leather, and when flnished must 

 be held in the middle, not with the fingers, but with forceps. 

 The next part of the process is to touch its edges slightly 

 with one or other of the cements before enumerated (the 

 simple gold-size wiU be found to be the best, as it is most 

 free from colour), the cover being held with the forceps, the 

 brush or finger with a very small quantity of the gold-size, 

 may be gently passed around each edge. This being done 

 the next step is to lay the cover upon the object, which 



