O BOTANICAL MICROTECHNIQUE. 



41 ff.). Objects which have become strongly colored in 

 drying may best be bleached by eau de Javelle (cf. 12, 4). 



III. Maceration. 



8. In many cases, especially when concerned with the 

 size, form, or structure of the membrane of the various 

 cells, it is desirable to separate an organ into its compo- 

 nent cells. This proceeding, which is commonly known as 

 maceration, depends upon the fact that the middle lamella 

 which is present between adjoining cells is dissolved by 

 various reagents, so that the cells separate from each other. 

 The ready solubility of the middle lamella depends, accord- 

 ing to the researches of Mangin (IV and VI), in most cases 

 upon the fact that it consists of various pectic compounds. 

 Thus one can bring about an isolation of the cells in very 

 many objects by treating them first with acid alcohol and then 

 with ammonia (cf. 295). 



Besides these, one may use many other and varied media 

 for the same purpose. Thus it is sufficient in many cases to 

 place the tissues for a time in boiling water or dilute acid, to 

 completely isolate the separate cells. This may be accom- 

 plished, according to Solla (I), in juicy fruits by oxalic acid 

 or tartaric acid, in potatoes and carrots by acetic acid. The 

 endosperm of Phytelephas is, moreover, separated into its 

 cells by chlorine-water or caustic potash in a few days, or by 

 hydrochloric acid in two minutes. 



In general, however, more energetic reagents are neces- 

 sary for the isolation of the separate cells, or at least pro- 

 duce that result more quickly and certainly. 



9. The following macerating agents are especially adapted 

 to more general use. 



I. Schulzes Maceration Mixture (HNO 3 ana KC1O 8 ). 

 This is still most frequently used for maceration. It is best 

 used by putting small pieces or slivers of the organ to be 

 treated into a test-tube containing about 2 ccm. of ordinary 

 concentrated nitric acid, adding some crystals of potassium 

 chlorate, and then warming the test-tube until bubbles are 



