720 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



Radais' Microtome with Vertical Slideless Carrier.* — This in- 

 strument, designed by Radais, belongs to the class of microtomes in 

 which the histological object borne by a carrier receives a vertical move- 

 ment. It is the knife which governs the adjustment and regulates the 

 thickness of the section. The mechanical arrangements of the various 

 parts are essentially different from the instruments hitherto in use ; the 

 results attained are marked by easy manipulation and an evenness of 

 section, which remains uniform even in the weakest section-strengths. 



Fig. 122 shows the apparatus arranged for celloidin sections. The 



Fig. 122. 



carrier is guided in a straight-lined course by means of two Watts 1 

 balance-wheels, movable between conical steel points. Such a kind of 

 adjustment lends itself to a very exact control, and obviates the work- 

 ing-space required for the slides generally recommended. Indeed it is 

 evident that in many machines the unequal pressure of the oil layer is 

 the main cause of the irregularity of the section thickness, and, more 

 over, the fouling is very considerable. In the axle movements between 

 the points the upper planes are in no wise exposed to the dust, the 



Zeitschr. angew. Mikr., ix. (1903) pp. 206-9 (2 figs.). 



