374 THE AMERICAN MONTHLY [Dec, 



erly arranged on the table of the freezing microtome, 

 covered with a few drops of anise oil, and then frozen 

 by means of an ether spray or any of the other freezing 

 appliances. 



The advantages claimed for this method are ; (1) the 

 sections can be cut by the freezing process from alcoholic 

 specimens ; (2)the edge of the section knife is not injured 

 by the congealed oil, as invariably follows the section of 

 tissues frozen in an aqueous solution; and (3) the tissue 

 is frozen much more quickly and when congealed it re- 

 mains so much longer than when frozen in the ordina- 

 rily used media which enables a larger number of 

 sections to be cut at a single freezing. The sections are 

 removed to alcohol, hydrated, stained, dehydrated and 

 mounted as if cut by the paraffin method. The necessi- 

 ty of a thoroughly practical process by which tissues 

 can be cut from alcoholic specimens and prepared for 

 microscopic examination in a short time is keenly felt 

 especially in pathological investigations. The method 

 suggested by Kuhne, therefore, filled a much needed want 

 in this particular. The time saved, however, is not so 

 great as at first imagined, but the elimination of the par- 

 affin infiltrating process is sometimes especially desira- 

 ble. 



More recently Coats (^^) has applied anise oil as a med- 

 ium for holding blocks of tissue to the table of the freez- 

 ing microtome without previously infiltrating them with 

 the oil. He does not find the anise oil satisfactory as 

 an infiltrating substance, but highly recommends it as a 

 medium in which to freeze tissues. He proposes a mod- 

 ification of Kuhne's application of this substance which 

 materially shortens the time necessary to section and 

 mount tissues for examination. His method is as follow : 



The tissue or organ from which sections are to be 

 made is cut into small blocks 2-4mm. in thickness and 



*T"he Journal of Pathology and Bacteriology, II. (1894), p. 492. 



