AND HOW TO USE IT. 243 



flap are marked off into two equal squares, E C, E' C, C D'. 

 The squares E B, A C, and E' B', A' C are doubled into two 

 parts across the diameters A B, A' B', and these triangular folds 

 thus made are pinched up and pressed against the end of the box 

 to support it. They are retained in position by the remainder of 

 the end fold, represented by A A' D D', being turned back over 

 them (Figs, i and 2). If the student prefers to do so, he can buy 

 a small box made of tin, price 3d., from Stanley, London. 



Melt the wax mass, take the specimen upon a needle, and 

 having removed the superfluous absolute alcohol (in which the 

 tissue ought to have been immersed for at least ten or fifteen 

 minutes before the operation is commenced) with blotting paper, 

 half fill the paper box with the melted wax, and dip the specimen 

 in several times until it is thoroughly covered with thin layers of 

 wax. Allow it to cool, and place the tissue on the wax in the 

 box at one end, and fill the box with melted wax ; and after it has 

 hardened mark on the outside the position of the tissue. When 

 quite hard, turn out the wax and the tissue by opening the ends of 

 the box, and place for a few minutes in methylated spirit. The 

 tissue is now ready for cutting. It is as well to shave off" the 

 corners of the wax, and also to cut off several thin slices from the 

 end near which the specimen is with a sharp knife or scalpel. See 

 that the razor may not be blunted by cutting too much wax. 



Cutting Sections with the Microtome.— At the present time 

 there is such an immense number of these instruments, that it 

 makes it rather difficult to advise students. I should recommend 

 them to see the various kinds and learn the points in which they 

 differ, to enable them to see which they prefer. The following are 

 the chief which I shall only just mention, as further particulars 

 can be obtained from looking at the various books on histology or 

 makers' lists : — Ranvier's microtome, a modification of which is 

 made by Beck ; Stirling's microtome, which is on the same prin- 

 ciple as Ranvier's, but is larger and fixed to a table with a screw ; 

 Rutherford's, which has a trough, which may be used to contain a 

 freezing mixture of ice and salt (recently, however, an ether spray 

 has been adapted to it; see Lancet, 1885). Rivet's is another 

 form of a microtome, in which the razor is arranged to slide at a 



