THE MICROSCOPE. 103 



held in one hand between the thumb and fingers and with a sharp 

 razor in the other, by a sweeping cut tolerably thin sections can be 

 obtained. The upper surface of the knife should be deeply concave 

 and kept flooded with alcohol. These sections are floated on a 

 slide and a few drops of Mailer's fluid placed over them. This is 

 allowed to cover them completely and to make a pool around them 

 for some seconds. The cover glass is then applied and by aid of a 

 pencil or strongly mounted needle, steady gentle pressure is made 

 on the centre of the cover until the nervous matter becomes a thin 

 transparent film. The superfluous fluid is removed by rinsing in 

 water and the slide is then transferred to alcohol. In about thirty 

 or forty seconds the slide is removed from the dish of alcohol and 

 while one edge of the cover-glass is steadied by the fingers, the 

 blade of a penknife is gradually inserted beneath the opposite edge. 

 The thin film will be left floating on the glass-slide or adhering to 

 the cover-glass. The specimen is washed to free it from spirit by 

 inclining the slide and allowing drops of water from a large camel's 

 hair brush to flow over it. 



2. The staining stage. A drop of a one per cent, solution of 

 aniline black is placed on the film and as soon as the requisite color 

 has been acquired, the slide is transferred to a vessel containing 

 water and gently lowered in it. By gently moving the water above 

 it with a brush the superfluous dye floats away. Other staining 

 agents, notably carmine, may be used. 



3. The mounting stage. All fluid is drained off the specimen 

 and it is placed under a bell jar with sulphuric acid. When per- 

 fectly dry add oil of cloves. This is removed when it has rendered 

 the film transparent and dammar added and then the cover-glass. 



The Sankey method. Another excellent method was described 

 in the April number of the Quarterly Microscopical Journal of 1876- 

 Sections are cut as by the above method, only they may be as thick 

 as the one-tenth of an inch. They are stained in a 7 p. c. solution 

 of aniline blue-black. In three hours the staining is removed and 

 water added until it washes away the excess of the staining. The 

 specimens are floated on a clean slide, allowed to drain, and then 

 exposed to the air in a dry place for twenty- four or forty-eight 

 hours. At the end of this time the section will be firmly dried to 

 the glass. It is now in a condition to have its upper surface planed 

 off with a razor or other suitable instrument, taking care not to 



