E. T. NEWTON ON THE PREPARATION OF SOFT TISSUES. 259 



somewhat minutely the construction of this machine, an account of 

 which will be found in the " Quarterly Journal of Science " for 

 January, 1874, p. 128. This machine may be obtained with the 

 top plate made either of brass, iron, glass, or plated ivith nickel^ 

 each of these substances having been proposed by different persons 

 as the most suitable for the knife to work upon. 



The machine which the author has been in the habit of using is 

 constructed upon the same general plan as Stirling's ; but it has a 

 side screw for compressing the object, and the screw for raising 

 the plug is firmly and carefully adjusted, and the head gra- 

 duated so as to indicate a rise of the plug of ywoo ^^ ^^ inch. 



A machine made by F. H. Ward, Esq., M.R.C.S., and exhibited 

 at the meeting, was of very similar construction to the author's ; 

 but was provided with a freezing trough and a glass top plate ; in 

 addition to this there was an arrangement by which the central 

 aperture could be reduced in size to accommodate smaller objects 

 and the graduation of the head of the screw was arranged on an 

 improved principle. 



2nd. — Machines in which the Edge of the Cuttinu Instrument 



DOES NOT come IN CONTACT WITH ANYTHING BUT THE OBJECT TO 

 BE CUT. 



Two machines of this description were noticed ; the first of these 

 was of German construction, and consisted of a plate of metal 

 about 8 inclies long, 2-^ inches wide at one end, and 3 inches wide 

 at the other, and about ^ of an inch thick; this was fixed by one of 

 its longest edges to the middle of another plate of metal which 

 formed the base for the whole apparatus. Upon each side of the 

 upright plate there was a kind of ledge or shelf ; one of these was 

 parallel with the base, while that upon the opposite side was 

 parallel with the top edge of the upright plate, and consequently 

 formed an angle with the base. Upon the horizontal ledge a block 

 of metal was fitted so as to be able to be moved backwards and 

 forwards ; to the top of this block a razor-like knife was attached. 

 The oblique ledge was fitted with a similar movable block, and upon 

 this was a contrivance for holding a piece of wax containing the 

 object to be cut. By this arrangement the razor remained at 

 the same level when the block to which it was attached, was 

 moved from one end of the horizontal shelf to the other, while 

 the object was gradually raised when the block to which it was 



