332 



SUMMARY OF CUKKENT RESEARCHES RELATING TO 



By making the tube g of mica, the object is found to retain the cold much 

 longer than is the case with other constructions. A is the plate on which 

 the preparation is laid ; g, the mica cylinder ; B, the lower part in which 

 the ether spray tubes are fixed. No. 1 tube is from the bellows ; No. 2 

 takes the air to the ether bottle ; No. 3, the ether bottle spray point ; and 

 No. 4 is the overflow pipe for the excess ether. 



The glass plate G serves as a support for the knife ; h is divided in 

 order to determine the thickness of the sections (1 division = 1/200 mm.) ; 



Fig. 8,1. 



C is the micrometer-screw which raises the object ; R is the screw which 

 fastens the instrument to the table ; D is the ordinary form of knife, and 

 E a stilet for clearing the spray points without enlarging their openings. 



Fig. 85 shows a similar contrivance adapted for use with a slide micro- 

 tome. 



Jung's Sliding Microtome for very large objects. — As this micro- 

 tome of Herr E. Jung (fig. 86) corresponds in the construction and use to 

 the smaller instruments, it is only necessary to describe the provision for 

 cutting large objects. 



The knife is to be placed considerably higher in front than behind, in 

 order to lessen the pressure on the objects. In order to satisfy all demands, 

 the knife-rest is adjustable. The knife is so arranged that the whole length 

 of blade can be used, and then the screw c is fairly tightly screwed down. 

 As strong knives, even of a length of 36 cm., easily give, a knife-support 

 has been constructed ; this is fastened by the screw c' to the carrier. The 

 support is arranged parallel with the back of the knife M ; if the extremity n 

 be slightly pressed backwards so that it touches the knife, it is then fixed 

 in this position by the screw o (scarcely evident in the illustration). 



This done, the spirit-vessel Sj) can be arranged in a position which will 

 not interfere with the free movement of the knife. In order that a stream 

 of spirit may follow the knife over the object, the following arrangement is 

 adopted. The spirit-vessel Sp turns round an axis on the column h; to it 

 is joined the arm L, which carries in front the fine tube r (connected with 

 t t'), and also the rod p ; the latter is movable perpendicularly, and to its 

 lower end a bridge or grip with two small rollers { and i' is fastened. The 

 rod p is so placed that on each side of the metal strip h, screwed on to the 



