PHILADELPHIA 
microtomes ana Apparatus for 
microtomp. 
LABORATORY MICROTOMES 
The long experience of the manufacturers in the construction of microtomes 
and the large number which have been made, has enabled the defects to be over- 
come that are inherent in most of the forms, and improvements to be added which 
permit work of the utmost precision to be done, with a comfort and facility not 
possible in other constructions. 
The movable parts are fitted with an exactness never surpassed m the con- 
struction of a microtome, and superior to that of most of the forms offered as first 
class In addition to the other new features, one important innovation has been 
introduced of rounding off the corners of the instrument, thus making it not only 
pleasant to handle, but obviating the liability of abrading the skin when working, 
which is of considerable importance where infectious material is to be handled. 
The unpolished parts are heavily enameled, and the finished portions nickeled to 
prevent rusting. 
The Microtomes may be described as consisting of three parts : 
The Stand, consisting of the Base, the curved Arm and the horizontal 
V-shaped Bed, 
The Knife Block, which carries the knife, and 
The Carriage, adjustable on the vertical portion of the stand, and carrying 
the Object Clamp, and the entire Feed Arrangement. 
The Stand is of one solid casting, which insures absolute rigidity of all 
the parts. 
Removable metal pan in the base collects the drip from the knife. 
The Knife Block, carrying the knife, slides on three narrow, perfectly parallel 
plane surfaces, is triangular in section and of unusual lehgfth, to insure perfect 
uniformity of motion when cutting, and to prevent the possibility of any vertical 
or lateral displacement of the knife, even when cutting very hard substances, and 
securing the minimum of friction compatible with these qualities. The knife is 
clamped to the upper surface of the block by a thumb screw which slides in a 
T-shaped groove, extending along the entire upper side of the block. This 
arrangement permits the adjustment of the knife to any angle with the object, and 
to any position on the block. Each block is carefully fitted to the bed, and works 
with extreme delicacy and regularity of movement. 
The Carriage is a stirrup shaped solid casting, movable on a perfectly 
fitted V slide along the whole length of the front of the Microtome Stand. 
It can be clamped perfectly rigid at any point by means of the thumb screws 
at either side. The movable feature of the carriagfe is a very important one, 
as it enables the object to be perfectly adjusted to the knife, and permits the 
use of the whole edge of the knife. No other Microtome made is provided 
with this convenience. 
It will thus be seen that this Microtome is adapted for both celloidin and 
paraffine work, including serial sectioning. 
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