16 



screw. The pitch of the screw is 1 min., and the head 

 ivided into 100 parts. so that a rise of 0*01 mm. can 

 be read. Two tubes for holding objects fitting into the 

 well are provided. The sections are cut by an ordinary 

 razor sliding upon te srlass plate. 



K. i^. 1887. Made by C. / 



64. Microtome of the same general structure as Xo. 

 63, with razor. 



1876. 



65. Microtome, similar in principle and construction 

 to Nos. 63 and 64, for cutting embedded materials. / 

 15s. 



Exhibited by Rigg's Technical 

 1889. 



66. Microtome, consisting of two elongated iron 

 troughs side by side ; one is horizontal, the other has a 

 slope of 1 in 20. In the former slides a block which 

 carries the razor, whilst in the latter is a block provided 

 with a clamp to carry the object to be cut. This can 

 be moved up the incline by a microm -\\ -. which 

 can be clamped at any point on the slope. The razor is 

 moved to and fro along one slide, and between even- 

 forward stroke the object is moved a little up the other. 

 As the incline is 1 in 20, the pitch of the screw 0*3 mm., 

 and the head of the screw is graduated into 13 par: 

 rise of O'OOl mm. can be brought about. 



With the instrument is an object holder of Koch's 

 pattern. 



K. 31. 1887. Made by E. Jung, Heidelberg. 



67. Microtome on the same principle as Xo. 66, but 

 with the following modifications : 



The razor clamp is made to hold the knife at any 

 point, and the carrier has an arrangement to prevent it 

 from rising in the groove. The divided drum on the 

 micrometer screw has an arrangement whereby a catch 

 falls into a notch either once or several times in each 

 revolution as desired. The object holder has move- 

 ments of rotation in two directions, so as to facilitate 

 the cutting of the object in any given plane. There is 

 an apparatus for freezing tissues to be cut by the ether 

 spray, which can be fixed upon the object carrier. There 

 is also a holder for cutting botanical and other objects 

 when fixed in pith. Made by R. Jung, Heidelberg. 



K. 24. 1889. 



