BRIEFER ARTICLES 



A FREEZING DEVICE FOR THE ROTARY MICROTOME 



(with one figure) 



A few years ago Osterhout 1 figured and published an account of a 

 simple freezing device to be used in connection with various sorts of 

 sliding microtomes. Later 2 he published an account of a simple freezing 

 microtome in which he made use of a knife of a plane for cutting on 

 account of its rigidity. In each of these devices, the freezing chambers 

 being stationary, they are both adaptable to the use of brine, carbon 

 dioxide, or other substances for freezing. These devices have been of 

 considerable service in the preparation of sections of living tissues. 

 However, if one wishes sections in large quantity and of uniform thick- 

 ness, and particularly if thin sections are desired, it is found that a 

 sliding microtome of almost any construction is inadequate, and to 

 manipulate it requires considerable dexterity. 



It occurred to the writer that the Osterhout apparatus for freezing 

 with brine might be modified in such a way as to make it usable with a 

 rotary microtome of any make, and thereby increase its efficiency and 

 enlarge the usefulness of both pieces of apparatus. The adaptation was 

 made and the results have proven so satisfactory that a brief account 

 of the apparatus seems desirable. 



The accompanying photograph of the apparatus will serve as a basis 

 for the description. It is simple and easy to construct, consisting of a 

 2X10 board 3.5 ft. long for the base, and 2 upright pieces fastened at 

 the base and braced by a cross-piece about one-third of the distance up. 

 A bolt passes through the base and the center of the cross-piece, and 

 another through the upright pieces just above the cross-piece to make 

 the apparatus firm. The upright has been lengthened in this case to 

 receive larger receptacles than were originally used. The wheel is 20 

 inches in diameter and 1 . 5 inches thick, making the whole device about 

 5 ft. high. The wire to hold the pails is firmly fastened in the middle 

 to the grooved wheel. The rubber tubing is of stiff white rubber. When 



1 Osterhout, W. J. V., A simple freezing device. Bot. Gaz. 21:195-201. figs. 6. 



1896. 



, Univ. Calif. Publ. Bot. 2:73. 1904. 



Botanical Gazette, vol. 63] ■ 



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