INTRODUCTION. 



HISTOLOGICAL REQUISITES. 



The student of Histology requires the following apparatus : 



1. A compound microscope, capable of magnifying from fifty to three hundred diameters 

 linear. 



2. Two short, strong, sharp-pointed needles, fixed in wooden handles, 

 at least five inches long, leaving about half an inch of their point pro- 

 jecting (fig. i). Each student ought to make these needles for himself. 

 Ordinary sewing needles may be conveniently fixed in crotchet-holders. 



3. A pair of steel fjrceps, which must not be too broad at the 

 points. 



4. A hollow ground razor, for making sections with the hand (p. 

 xxxvi). The razor ' made for the army ' by John Heifor is the best. 



5. A pair of sharp-pointed scissors. It is advantageous for some purposes to have a pair 

 curved on the flat (fig. 2). 



Fig. i. , END OF A 



MOUNTED NEEDLE. 

 Natural Size. 



2. SCISSORS CURVED ON THE FLAT. Natural Size. 



6. Three or four small camel-hair brushes duck size for putting on the cement used to 

 seal up the preparations. It is convenient to keep Nos. 2, 3, 4, 5, and 6 in a small box or in a 

 small drawer in one's work-table. 



7. Glass slides. It is desirable to have two sizes. The glass should be free from specks 

 and not too thick, and the edges ought to be ground. 



(a) Six dozen ground-glass slides 3x1 inch. 

 (&) Three 3x1^ 



8. Cover-glasses. I prefer the circular form, though many observers use squares. The 

 one point of importance about them is that they cannot be too thin. It is well to measure 

 their thickness, and this can be easily done as described at p. xxv. Messrs Chance, of 

 Birmingham, make cover-glasses of three thicknesses, which are numbered Nos. I, 2, and 3. 



b 2 



