682 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



has resulted from attempts to avoid long handles or other belongings of 

 the baskets, that prevent the close fitting of the plates of glass used to 

 cover the paraffin dishes. 



Fia. 191. 



Fig. 192. 



Fig. 193. 



Francotte's Sliding Microtome.* — Dr. P. Franeotte has designed an 

 instrument capable of making most perfectly regular sections of a limited 

 size, 5 mm. at most. The body of the microtome is like Eanvier's, and the 

 object to be cut is placed in a cylinder which slides in the microtome tube. 

 The latter piece does not rub against the metal walls, but is supported in 

 the cylinder by means of pieces of cork. At the base of the tube is a scale 

 for noting the movements of the screw, and at the side is an index for 

 showing in what limits the piece can move. 



Upon the circular table of the microtome is fixed by three screws a 

 plate larger than the table. In the centre is an opening in order that the 

 piece may be raised, and at the side a groove with triangular vertical 

 section and sharp edges ; within this groove the object-carrier runs. The 

 carrier slides merely on two longitudinal bands so as to lessen the friction 

 as much as possible. The groove maintains a rectilinear and regular 

 movement ; the two metal bands keep the knife moving in the same plane. 

 The razor is fixed to the carrier by means of a metal piece and two screws, 

 and in order to obtain the desired stability the instrument is fixed to the 

 work-table by a binding screw. For the rest, the manipulation of the 

 instrument is very simple, and M. Franeotte thinks it will suffice for most 

 histological investigations. 



Ryder's Automatic Microtome.t — This instrument (figs. 194 and 195) 

 has been devised by Prof. J. A. Eyder, in order to facilitate tha preparation 



* Bull. Soc. Beige Micr., xiii. (1887) pp. 149-50. 

 t Amer. Natural., xxi. (1887) pp. 298-302 (2 figs.). 

 (1887) pp. 179-83 (2 figs.). 



Cf. also The Microscope, vii. 



