244 Tue Microscope. 
slide lies in the ease with which they are stained, and another 
is that no matter how delicate or how complicated, every sec- 
tion and every part of a section is forced to occupy its proper 
place and ail chances of disarrangement of parts entirely disap- 
pear. Sections are covered far more readily and more evenly 
on the slide than is the same tissue in the mass, and when one 
by practice becomes familiar with the technique he has no de- 
sire to return to the flesh pots of Egypt. To be sure the steps 
are rather numerous but when one has mastered them they come 
like second nature. There is a philosophy in all microscopic 
- work and as soon as one understands why each step is taken, 
the whole is clear as day. 
In mounting sections on the slide by the collodion method 
I have found it most convenient to coat a large number of the 
slides at the same time with collodion and afterward as required 
for use to paint the spot which the sections are to occupy with 
oil of clove. The other method paints the slides as wanted 
with a mixture of clove oiland collodion. In applying the collo- 
dion a glass rod is the most convenient instrument and it should 
be passed but once over the slide. 
Unless considerable care is taken the collodion method will 
not work satisfactorily in all cases and for this reason: Not in- 
frequently one gets on too much oil of clove and then the sec- 
tions float out of their proper position. This of course can only 
be avoided by using just enough oil of clove to render the col- 
lodion sticky and not enough to make it fluid. Even then when 
dissclving away the paraffin with turpentine one will occasion- 
ally be annoyed by having some of his sections float away. 
The cause is not far to seek. The slide was not left long enough 
on the water bath and hence a little of the clove oil still re- 
mains. They should be kept at an elevated temperature until 
not the slightest odor of the oil can be recognized. Then all 
will be safe. 
In the lac method of fastening the sections one frequently 
has difficulty in dissolving the lac. Freshly bleached lac is re- 
quired and it should be bleached in the sun and not by chemic- 
als as is now the practice. In case the lac becomes old it need 
not all be thrown away for on breaking open the lumps the in- 
terior will be found suitable for use. It should be dissolved in 
