34 MICRO-CHEMICAL REAGENTS. 



CHLORATE OF POTASSIUM. 



This reagent is used with nitric acid, either in a 

 concentrated aqueous solution, or, better, in the 

 crystalline form, for the destruction of the " middle 

 lamella" and the consequent isolation of cells, 

 especially in investigations of wood. 1 The mix- 

 ture, the so-called Schultze maceration-medium, is 

 boiled for a few minutes in contact with pieces of 

 the tissue to be studied. After careful washing in 

 alcohol, these macerated preparations may be pre- 

 served in glycerine. This process must be carried 

 on at a distance from microscopes and other appar- 

 atus that can be injured by the gases developed. 



The Schultze mixture has also been found useful 

 as a reagent for suberin. Thin sections are boiled 

 for a long time in it ; all parts of the cell-wall soon 

 become clear, but those which contain suberin 

 possess dark and sharp contours and resist the 

 action longer than the others, though finally they 

 become distorted, abruptly swell, and melt to form 

 rounded drops of eerie acid, which are soluble in 

 ether, benzol, chloroform, caustic potash, and boil- 

 ing alcohol. In the process a part of the suberin 

 is dissolved by the reagent, only a part being 

 changed into eerie acid. Membranes which are 



l Sanio: Bot. Zeitung, 1863, p. 362, note; Anatomic der Kiefer. 

 Jahrb. fur wiss. Bot., IX. Hohnel : Ueber Kork. Berichte der wiener 

 Akad., 1877, Abth. I. Schacht : Das Mikroskop, 1855, p. 27 ; Anatom. u. 

 Physiol. der Gew., I., p. 14. Dippel : Das Mikroskop II., p. 101. Nageli: 

 Das Mikroskop, 1877, p. 474. 



