332 The Microscope. 



these tubes it is necessary to handle them separately, a matter 

 of time and inconvenience. In the device herewith illustrated, 

 a lot of brass knife clamps are fastened, by means of lugs 

 pinched and bent back from the sides, or a tack or screw 

 through the centre, to a piece of card or wood-board, or for 

 transportation, the bottom of a cigar box. When thus arranged 

 they may be hung on the wall, carried about the room, examin- 

 ined, etc., by the dozen, and in this way time saved and incon- 

 venience obviated. Tiie clamps ma}'^ be had on order of almost 

 any hardware house. 



ELEMENTARY MICROSCOPICAL MOUNTING— L 



DR. A, M. WEBSTER. 

 PART I. — PREPARING FOR WORK. 



AMOUNTED microscopic object is one that is sealed within 

 a cell whose upper and lower surfaces are of glass, the cell 

 margin itself being sometimes square, sometimes circular, and 

 formed of substances that may vary almost as the wish of the 

 microscopist. The essential feature of the mount are the two 

 glass surfaces, the cell wall that surrounds the object, and the 

 medium in which the object is immersed ; that- is, all of the 

 preparation is important to the success of the mount, and for 

 the pleasure of the microscopist, as well as for his instruction. 

 There are several reasons for sealing the object within the 

 transparent cell. It can thus be preserved for a-i indefinite 

 time and always be ready for examination. It is protected from 

 the dust, and from the ravages of insects that, under certain 

 conditions, will destroy our microscopic objects, as well as the 

 carpets and other materials in our houses. Perishable objects 

 can be preserved in a cell unchanged and in minute portions 

 such as the microscope can easily deal with. They can be sur- 

 rounded with certain preservative media so that their optical 

 qualities shall be so changed that the specimens can be studied 

 with the instrument, whereas, under other conditions, they 

 could be seen only with the naked eye or with the pocket lens, 

 and in large mass. For the microscopical study of an object, 

 therefore, that object must always be passed through certain 

 processes, and be " mounted," as the microscopist calls the final 

 sealing: between the two glass surfaces. 



