xxx INTRODUCTION. 



advisable if possible to procure both object-slides and cover- 

 glasses of a definite thickness. 1 



Cover-glasses, if thin, are not easy to manipulate without 

 risk of breakage. On p. 10 will be found described a method 

 of cleaning them before use, which I [Ed.] have found useful 

 for students. While keeping the stock in the thin boxes in 

 which they are sent, a dozen or so are put out at a time into 

 a kind of trough, made by taking a piece of hard wood, about 

 2J inches long, 2 inches wide and 1 inch thick, and cutting 

 out a portion of its top in the form of a slope or inclined 

 plane, flush with the top of the block of wood at one end, 

 and with a rim left along the sides and at the other end. 

 Upon this flat sloping surface the cover-glasses lie quite 

 safely, and can easily be moved with the finger, especially if 

 slightly damped. 



Further necessary are a plane- and some hollow-ground 

 razors ; a fine and a coarse pair of steel forceps and a pair 

 with ivory points ; a finely pointed pair of dissecting scissors, 

 for which fine embroidery scissors will serve ; a pair of needle- 

 holders, somewhat after the fashion of crochet needle-holders, 

 but so arranged that they will hold the finest needles firmly ; 2 

 needles from No. 8 upwards, for these holders ; some scalpels, 

 some fine camel-hair or sable brushes ; 3 a small vice, such as 



3 1 had for years considerable difficulty in obtaining these latter in England 

 {where, nevertheless, they are mostly made), but now obtain them direct from 

 the manufacturers, Messrs. Chance Bros. & Co., Limited, Glass Works, near 

 Birmingham. They are designated " No. 1," average T ^ inch (i.e., O15 mm.) 

 in thickness, and cost in square form 3s. 3d. per oz. They are made in various 

 sizes. Chances also manufacture a somewhat thicker, and therefore stronger, 

 cover-glass at 2s. 6d. per oz. Glass circles are somewhat dearer. Chances 

 formerly manufactured specially thin microscope slides of 9 oz. crown-glass, 

 ground and with polished edges, at 4s. lOd. per gross. These were of very fine 

 quality and practically uniform thickness, but owing to lack of demand they 

 have ceased to manufacture them. 



2 With care, needles can, by the aid of tweezers, be forced with their eye 

 nd into thin wooden paint-brush handles. According to the length that 

 projects, the needle will be more or less stiff. 



5 For transferring sections from fluid to a slide the camel-hair brushes can 

 be used as described on p. 27 ; or a simple " section lifter" can be made from 

 a straight piece of stout copper wire 4 or 5 inches long, by beating out thin 

 about half-an-inch or so of one end, cutting the edge smooth with scissors, and 

 then bending the wire above the broadened part to an angle of about 135. 



