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Isabel Soar 
II. Concentrated sulphuric acid. 
The cellulose and lignocellulose walls swell, the former rapidly 
dissolving in the acid, whereas the latter carbonise and dissolve much 
more slowly. Suberised and cuticularised layers do not swell when 
in contact with the acid and are not carbonised by prolonged treat¬ 
ment with it. 
III. Dilute sulphuric acid. 
This was found to be very useful when used as a clearing agent. 
By mounting sections in it the presence of pits in the walls of the 
cells could be demonstrated clearly. 
IV. Phloroglucin and hydrochloric acid. 
If a solution of phloroglucin is allowed to act on the sections for 
about two minutes, and the sections are subsequently mounted in 
strong hydrochloric acid, cellulose walls remain unstained, whereas 
lignocellulose walls are stained bright red and suberised walls are 
stained a deep pink. 
■ 
V. Eau de Javelle. 
By treating sections for twenty-four hours with eau de Javelle 
the nature of the lignified walls is changed, these acquiring the 
reactions of cellulose. Thus subsequent treatment with phloroglucin 
and hydrochloric acid produces no coloration in these walls. Suber¬ 
ised and cuticularised membranes remain unchanged by this treat¬ 
ment, and on the addition of phloroglucin and hydrochloric acid a 
pink colour is produced where these are present. 
If, after the section has been treated with eau de Javelle for 
twenty-four hours, concentrated sulphuric acid is placed upon it, 
both cellulose and lignocellulose membranes are rapidly dissolved 
without carbonisation occurring in the latter, and only the suberised 
and cuticularised layers of the walls remain. 
VI. Alcoholic solution of Sudan 111 . 
Sections show a red colour in suberised and cuticularised mem¬ 
branes only. 
VII. Alcoholic solution of alkannin. 
If this is allowed to act on sections for about two hours a red 
coloration is produced in suberised and cuticularised membranes 
only. 
