INTRODUCTION. XXXI 



used by watchmakers ; some pipettes, glass tubes and glass 

 rods ; watch glasses of various sizes, and glass disks of suit- 

 able sizes for covering them ; l china saucers as used for paint 

 boxes ; low glass bell- jars (receivers), in order to be able to 

 fit up moist chambers ; zinc frames, somewhat as represented 

 in half-size in Fig. 2, on which to place the object-slides 

 under the bell-jars ; 2 two bell-jars of suitable height, under 

 which to be able to place respectively the compound and the 

 simple microscope; and lastly, elder-pith. For working, a 

 tumbler of clean spring water is needed ; a saucer is useful 

 for dirty slides. 



FIG 2. 



The list of the necessary reagents is to be found at the 

 end of, this book. These reagents are in general best kept 

 in small squat bottles, holding about an ounce, tightly corked, 

 with the cork perforated, and holding in its bore a piece of 

 thin glass rod with rounded ends, by which a drop of the fluid 

 can be taken when required ; or similar bottles, stoppered, 

 with long tapering stoppers, can be obtained if preferred. 



1 Watch glasses can also be obtained, in pairs, ground to fit, and with 

 brass-wire clip to hold them together. These are exceedingly useful for 

 temporarily keeping a number of cut sections, etc., or for staining or other 

 operations which require micro-sections or material to be exposed to the action 

 of a small quantity of fluid for a considerable time. 



2 Slides can be also left upon these frames to dry, after permanent mount- 

 ing. If the frames cannot be kept perfectly steady, the slides may wriggle off 

 in time ; to prevent this, sheets of paper inch wider than the frame can be 

 bent over them on each stage, and the slides laid across these. By using 

 blotting paper for these sheets, and keeping wet, the bell-jar can be converted 

 into a convenient moist chamber for a number of slide cultures at room 

 temperature. 



