STAINING AND MOUNTING. 201 
with the alcohol and becomes transparent when the 
xylol is added ; and this transparency is the proof that 
the steps have been carried out properly. If the section 
looks opaque when held against a perfectly dark back- 
ground an additional dose of alcohol must be used, and 
the xylol applied again. 
Hematoxylin may be used in exactly the same way 
as hematin in the above process; it stains more quickly, 
but does not give quite such beautiful results. 
(2). Gram’s method as applied to sections; suitable 
for sections of diphtheritic membrane, organs containing 
anthrax bacilli, streptococci, staphylococci, &c. 
1. Xylol, two lots. 
2. Absolute alcohol, two lots. 
3. Water. These steps are always the same with 
paraffin sections, no matter what stains are to be used 
subsequently. 
4. Aniline gentian violet—five minutes. 
5. Gram’s iodine solution—three minutes or more. 
6. Absolute alcohol or methylated spirit—snttl no move 
colouy comes out, This step is best carried out as fol- 
lows :—Hold the slide by one end, keeping the fingers 
clean by using a duster or pair of dissecting forceps, 
and pour a little spirit on the section; rock it gently 
from side to side and notice the clouds of colour which 
it takes up. After a little time pour off the spirit and 
add a fresh lot; repeat the rocking, and pour off again. 
Do this until the spirit comes away quite clean and 
does not take up any colour from the section. This 
may take a long or a short time, and no definite rules 
can be laid down. 
In some cases decolorisation can be carried out best 
by the use of clove oil. This is applied when the spirit 
is wet with absolute alcohol (for it will not mix with 
