SPECIAL METHODS 
137 
LAND’S GELATIN METHOD 
It is sometimes desirable to get sections of partly disorganized 
material. A matrix is necessary to hold the parts in place, but 
dehydration may make the tissue unnecessarily hard to cut. 
Soak ordinary gelatin (which can be obtained at the grocery) in 
water until no more is taken up. Then drain off the excess water 
and liquefy the gelatin by heating. Place the material—previ¬ 
ously soaked in water—in the melted gelatin and keep it there 
for several hours. Place also in the gelatin some small blocks of 
hard wood to serve as supports in the microtome. The material 
to be sectioned is oriented in a gelatin matrix on the supporting 
blocks, cooled until the gelatin sets, and then placed in strong 
formalin to harden the gelatin. In cutting, flood the knife with 
water. 
If the material is to be stained, stain it in bulk before putting it 
into the gelatin, since the gelatin stains very deeply. Of course, 
the gelatin could be dissolved with hot water, or hot water and acetic 
acid, but all the advantage of a matrix would be lost. 
It would be worth while to try this method thoroughly with soft, 
succulent tissues and with hard tissues which become still harder 
if dehydrated. 
SCHULTZE’S MACERATION METHOD 
Various solutions are used to separate a tissue into its individual 
cells. These solutions dissolve or weaken the middle lamella so that 
the cells are easily shaken or teased apart. Schultze used strong nitric 
acid and potassium chlorate. Put the material, which should be in 
very small pieces, into a test-tube; pour on just enough nitric acid 
to cover it, and then add a few crystals of potassium chlorate. Heat 
gently until bubbles are evolved, and let the reagent act until the 
material becomes white. Four or five minutes should be sufficient. 
The fumes are disagreeable and are very injurious to microscopes. 
Pour the contents of the tube into a dish of water. After the material 
is thoroughly washed in water, it may be teased with needles and 
mounted, or it may be put into a bottle of water and shaken until 
many of the cells become dissociated. 
After a thorough washing in water, the material may be stained. 
The large tracheids of ferns, dissociated in this way and stained in 
safranin or methyl green, make beautiful preparations. 
