OF MICROSCOPIC OBJECTS. 1 



quantity of turpentine until the air is thoroughly expelled, they 

 can be easily finished upon the slide, especially when balsam and 

 chloroform are used. 



Insects supply us with another series of beautiful objects, viz., 

 the feet.* These are sometimes simply dried and mounted with- 

 out any medium, as before mentioned ; but most of them are ren- 

 dered much more fit for examination by using balsam in their 

 preservation, as it greatly increases their transparency. The 

 smaller kinds may be dried with gentle pressure betwixt blotting- 

 paper, and then immersed for some clays in turpentine, without 

 requiring the treatment with liquor potassae. This immersion will 

 render them beautifully transparent, when they may be mounted 

 in balsam in the usual manner. 



It is, however, sometimes found difficult to fix the feet when 

 expanded, in which state the interest of the object is greatly in- 

 creased. Mr. Ralph recommends the following mode : " First 

 wash the feet, while the insect is yet alive, with spirits of wine ; 

 then holding it by a pair of forceps close to the edge of a clean 

 piece of glass, the insect will lay hold of the upper surface by its 

 foot, then suddenly drop another small piece of glass over it, so 

 as to retain the foot expanded, and cut it off with a pair of scis- 

 sors, tie up and soak to get rid of air." Mr. Hepworth says that 

 he never found any difficulty in expanding the foot on a drop of 

 water or well-wetted slide, and laying a thin glass cover over it, 

 tying with thread, drying, and immersing in turpentine. 



The mouth, also, with its organs, is an interesting object in 

 many insects. That of the common fly is often made use of, and 

 is comparatively easy to prepare. By pressing the head, the 

 tongue (as it is commonly termed) will be forced to protrude, 

 when it must be secured by the same means as the foot, and may 

 be subjected to the soaking in turpentine, and mounted as usual. 

 The honey-bee is, however, very different in formation, and is well 

 worth another slide ; indeed, even in insects of the same class, the 

 differences are many and interesting. 



Another worthy object of study is the respiration of insects, 



* See Mr. Hepworth's interesting; articles on the fly's foot in the second 

 and third volumes of the Microscopic Journal 



