30 BOTANICAL MICROTECHNIQUE. 



42. I refrain from describing here in detail the various 

 microtomes and their manipulation, and merely remark that 

 I have obtained the best results with a relatively small 

 microtome by Schanze, namely, sections of I micron and 

 even of fractions of a micron in thickness. 



In this instrument, as may be seen in Fig. 14, the move- 

 ment of the knife, as well as the raising of the object, is 

 accomplished by the aid of screws. To obtain very thin 



FIG. 14. Microtome by Schanze. 



sections, one turns the disk which is connected with the 

 object-raising screw by a system of cogs. This shows di- 

 rectly I /* of thickness and permits the estimation of frac- 

 tions of that thickness.* 



I have also worked for a long time with a more elaborate 

 microtome by Aug. Becker (Gottingen) which was very 

 exactly constructed. 



[I have used with great satisfaction for serial sections of 

 objects imbedded in paraffine the Minot microtome. This 

 has the knife fixed, while the object is moved vertically past 

 its edge, being pushed forward by an amount equal to the 

 desired thickness of a section, at each descent, by an auto- 

 matic device. The operation of the instrument consists in 



* This microtome was constructed from the specifications of Prof. Altmann 

 and may be had of the mechanician M. Schanze (Leipzig, Briiderstr. 63.) 



