352 



CENTEAL SCIENTIFIC CO., CHICAGO, U. 8. A. 



No. 8904. 



No. 8918. 



8902. MICROTOME, Clinical and Diagnostic, with Automatic Peed, similar in construction to No. 

 8892, but with automatic device for moving the feed screw as the knife is returned for the 

 next stroke. Complete with object clamp for paraffme blocks up to 30x22 mm, but without 

 knife $35.00 



8904. MICROTOME, Clinical and Diagnostic, with Automatic Feed, same as No. 8902, but with freez- 

 ing chamber for carbon dioxide without knife or object clamp 40.00 



8906. MICROTOME, Clinical and Diagnostic, with Automatic Feed, same as No. 8902, but with both 



paraffine clamp and freezing chamber for carbon dioxide without knife 42.00 



KNIVES for Nos. 8902, 8904 and 8906, see Nos. 8897 and 8898. 



8910. MICROTOME, Automatic Laboratory, designed to do away with all sliding parts. The feed 

 mechanism is automatic, simple in construction, covered and protected from dust and drip- 

 pings. The microtome may be securely clamped to any laboratory table. It may be set to cut 

 sections of any desired thickness. Each division of the graduated scale marks 5 microns. 

 The extreme ends of the knife rest in carrier, and, as the lever handle moves the swing- 

 ing arms, the knife describes a flattened curve, corresponding to the double movement in free- 

 hand sectioning. By this manner of holding the knife by arms which are not parallel, the 

 entire length of its cutting edge is utilized, insuring uniform wear and permitting the cutting 

 of very large sections. This peculiar motion of the knife makes this microtome pre-emi- 

 nently fitted for cutting frozen sections. Complete with one knife and usual object clamp 

 for paraffine or celloidin, in case 60.00 



8912. MICROTOME, Automatic Laboratory, same as No. 8910, but fitted with No. 8940 Freezing 

 Attachment for Carbon Dioxide 70.00 



8914. MICROTOME, Automatic Laboratory, same as No. 8910, but fitted with No. 8942 Freezing 



Attachment for Ether 67.50 



For KNIVES for Nos. 8910 to 8914, see No. 8958B. 



8918. MICROTOME, Spencer Simplified Rotary, designed to meet the demand for a dependable instru- 

 ment of precision at a moderate price. A high degree of accuracy is attained by following 

 the same principle of construction which is used in the Spencer Eotary Microtome No. 8922. 

 The feed mechanism is independent of the up-and-down movement of the object. It is oper- 

 ated by a micrometer screw, cut two threads to the millimeter, to which is fastened a wheel 

 having 250 notches cut on its periphery. Each notch represents a thickness of two microns 

 in the section. The instrument will cut any thickness up to forty microns in multiples of two. 

 The total excursion of the feed is 30 mm. A crank provides a means for adjusting the object 

 to the knife with extreme delicacy and also for returning the object clamp to the position 

 necessary for starting a new series of sections. When the clamp has reached the extreme for- 

 ward position, the feed mechanism automatically ceases to work. 



The object clamp holder is moved up and down at the ends of two parallel hinged arms entirely 

 independent of the feed mechanism. The clamp may be rotated on its axis by loosening one 

 of the screws. It regularly takes in a block 28 mm wide and 16 mm thick. There is a provi- 

 sion by which the latter dimension may be increased to 22 mm. 



The whole instrument is rigidly made and runs extremely easily and quietly. It is finished in 

 crystal black and is supplied in a substantial case. Complete with one No. 8958B Knife with 

 handle and back for sharpening, and with three object disks 75.00 



