228 Wilson: Improved methods of utilising organised structures. XXVII, 2. 



The level base of the embedding chamber is formed by a brass 

 plate, figg. 1 and 2«, through which are bored two pairs of cylin- 

 drical holes, bj each about 3 mm in diameter. The distance between 

 the two pairs of holes will practically determine the length of the 

 embedding base. The precise interval between the individual holes 

 of each pair is of little importance, and will depend upon the width 

 given to the ends of the embedding chamber, which in turn will 

 determine the width of the paratiin block. The ends of the embed- 

 ding chamber are constituted by small thick rectangular brass plates, c, 

 set up upon the base-plate. They must be accurately perpendicular 



Fig. 1. Showing constituent parts of Wilson's paraffin embedding 



cliamber. 



a — Base-plate. 



b — Holes for dowel-pins of end plates. 

 c — End plates. 

 d — Dowel-pins of end plates. 



e — Sockets for accommodation of pins (/) of base-plate. 

 f — Pins round which the nerve-strands are stretched. 

 g — Splayed side-blocks which make up the sides of the 

 embedding chamber. 



to the latter, and accurately ])arallel with one another at a distance 

 corresponding with the extent of the chamber. They are firmly 

 held in position by projecting dowel-pins, c?, which fit accurately 

 into the pairs of holes in the base-plate above described. Further, 

 the lower edge or surface of each end-jilate is provided, midway in 

 tlie interval between the dowel-pins, with two narrow socket-holes, e. 

 These fit quite loosely over two small pins, /', projecting 2 or 3 mm 

 up from the base-plate, in which they are firndy fixed in the inter- 



