128 THE MICROSCOPE AND ITS REVELATIONS. 



what larger dimensions. These were formerly designated as c fishing 

 tubes;' the purpose for which they were originally devised having been 

 the fishing-out of Water-fleas, aquatic Insect-larvae, the larger Animal- 

 cules, or other living objects distinguishable either by the unaided eye or 

 by the assistance of a magnifying-glass, from the vessels that may contain 

 them. But they are equally applicable, of course, to the selection of 

 minute Plants; and they may be turned to many other no less useful pur- 

 poses, some of which will be specified hereafter. When it is desired to 

 secure an object which can be seen either with the eye alone or with a 

 magnifying-glass, one of these tubes is passed down into the liquid, its 

 upper orifice having been previously closed by the forefinger, until its 

 lower orifice is immediately above the object; the finger being then re- 

 moved, the liquid suddenly rises into the tube, probably carrying the 

 object up with it; and if this is seen to be the case, by putting the finger 

 again on the top of the tube, its contents remain in it when the tube is- 

 lifted out, and may be deposited on a slip of glass, or on the lower disk 

 of the Aquatic-box, or, if too copious for either receptacle, may be dis- 

 charged into a large glass cell (Fig. 120). In thus fishing in jars for any 

 but minute objects, it will be generally found convenient to employ the 

 open-mouthed tube c; those with smaller orifices, B, c, being employed 

 for 'fishing' for Animalcules, etc., in small bottles or tubes, or for 

 selecting minute objects from the cell into which the water taken up by 

 the tube A has been discharged. It will be found very convenient to 

 have the tops of these last blown into small funnels, which shall be cov- 

 ered with thin sheet India-rubber; for their action (like that of the stop- 

 per of the Dropping-bottle, Fig. 138) can then be regulated with the 

 greatest nicety by the pressure of the finger. 



127. Glass Syringe. In dealing with minute Aquatic objects, and in 

 a great variety of other manipulations, a small Glass Syringe of the pat- 

 tern represented in Fig. 106, and of about double the dimensions will be 

 found extremely convenient. When this is firmly held between the 

 fore and middle fingers, and the thumb is inserted into the ring at the 

 summit of the piston-rod, such complete command is gained over the 

 piston, that its motion may be regulated with the- greatest nicety: and 

 thus minute quantities of fluid may be removed or added, in the various 

 operations which have to be performed in the preparation and mounting 

 of Objects (Chap, v.); or any minute object may be selected (by the aid 

 of the simple Microscope, if necessary) from amongst a number in the 

 same drop, and transferred to a separate slip. A set of such Syringes, 

 with points drawn to different degrees of fineness, and bent to different 

 curvatures, will be found to be among the most useful ' tools 9 that the 

 working Microscopist can haVe at his command. 



Forceps. 



128. Forceps. Another instrument so indispensable to the Micro- 

 scopist as to be commonly considered an appendage to the Microscope, is 

 the Forceps for taking up minute objects; many forms of this have been 

 devised, of which one of the most convenient is represented in Fig. 107, 



