BAIRD &.TATLOCK (LONDON) LTD. 



1632-1635 



1636-1638 



1640 



Microtome Knife, Thoma's model, plano-concave, with handle adapted for clamping to 

 the knife carrier of the microtome. 



1632 T Length of cutting edge 36 centimetres .. .. .. .. ..300 



1633- 24 .. 1 13 



1634- 17 100 



1635- 12 . . . . 14 



Microtome Knife, Jung's model, plano-concave (requires knife-holder). 



1636 T Length of cutting edge 24 centimetres .. .. .. .. ..16 



1637- 17 .- 13 



1638 T 12 .. .. .. 11 



1639' Microtome Knives of finest English steel (Sheffield make). 



4f in. 6J in. 8 in. gj in. 



12/6 16/6 25/- 30/- each. 



1640 T Bardeen's Small Microtome by Leitz. 



This microtome consists of a hollow cylinder, terminating below in "a. hexagonal nut by which it should be 

 screwed to the gas cylinder. A hollow freezing stage with a spiral channel rises above. The interior of the cylinder 

 communicates with the external air through a fine hole, through which the carbon dioxide rushes against the 

 inner surface of the freezing stage after passing along the entire length of the spiral channel. 



The cylinder first described has sliding upon it another, carrying the knife-guides. These consist of two narrow 

 strips of glass upon which the knife should be rested during the operation of cutting 



The desired thickness of the section is obtained by turning the graduated disc. Each interval corresponds to 

 a thickness of o.ooi millimetre. 



In this form of instrument the freezing stage is fixed, whilst the knife-guiders rise and fall under the action of 

 the micrometer screw and a counter spring. 



The microtome is attached to the gas cylinder in the following manner. After unscrewing the cap on the 

 gas cylinder, remove the hexagonal nut screwed upon the lateral thread for its protection. Screw the microtome 

 upon this thread, and draw it up tight with a spanner. 



Price 1 15 



14 -CROSS STREET- HATTCHsT GARDEN, E-C 



318 



