54 The Microscope. 



method all fragile specimens containing the products of inflam- 

 mation may easily be cut without losing the contents of the 

 vessels into which the inflammatory exudate has taken place 

 The specimen is hardened in alcohol as above described, but is 

 allowed to remain forty-eight hours in absolute alcohol, from 

 which it is taken and placed in sulphuric ether for two days. 

 From the ether it is placed in a thin solution of celloidin, for 

 the purpose of soaking it through and through — seven to ten 

 days is sufficient to accomplish this end. 



The specimens are imbedded in paper boxes in the usual 

 manner, or as I do, imbed, and at the same time fastening them 

 to the cork. I wrap a cork with heavy writing paper, and allow 

 it to project an inch beyond the cork ; the cork forms the bot- 

 tom of the box. Pour upon the cork a thin film of the imbed- 

 ding solution, and allow it to dry. Moisten this film with a 

 drop of ether, adjust the specimen, add a little more of the cel- 

 loidin solution, and allow it to become semi-solid, thus fixing 

 specimen. Then fill the box with a thicker solution, wholly 

 covering the specimen, let stand in the air until semi-solid, re- 

 move paper and extra celloidin with a knife, and place in a 

 solution of 80 percent, alcohol for twelve hours, when the spec- 

 imen will be ready for cutting. Specimens when prepared in 

 this way may, when cut, be stained in the different staining 

 fluids. Care shonld be taken when clearing them not to use 

 oil of cloves or absolute alcohol, for both dissolve the celloidin. 

 Use alcohol of 95 per cent, and oil of origanum or oil of San- 

 ders. Where the former oil is used let the specimen remain 

 from two to four days. 



Celloidin comes in two forms — in plates and in shreds ; the 

 latter is to be preferred, as it if more easily dissolved. The so- 

 lution should be kept in a glass- stoppered bottle. 



The microtome which I use is one manufactured in Leip- 

 zig, Germany, and is known as the Schanze Microtome. It cuts 

 hardened specimens ; and fresh specimens may be frozen and 

 cut as easily as those hardened in alcohol. It has been widely 

 used upon the continent, and in all laboratories it has given 

 perfect satisfaction. It works rapidly and does its work well ; 

 it must be seen to be appreciated. Specimens may be cut as 

 thin as ??W of an inch, and to the size of a half dollar in diam- 



