40 BACTERIOLOGICAL DIAGNOSIS. 
When no properly cleaned slides are at hand the 
following method may be adopted, though it is not so 
good. Dip the end of a clean handerchief in strong 
‘spirit (absolute or rectified) and wipe the slide with it, 
using a considerable amount of friction. Now dry it 
with the special handkerchief mentioned above, heat it 
thoroughly in a smokeless flame, and allow to cool 
completely. Spread the film on the surface which was 
exposed directly to the flame. 
Cover-glasses are cleaned in the method advised for 
slides, and should be stored in strong alcohol smelling 
strongly of ammonia. They are wiped with the special 
handkerchief immediately before use. 
When cover-glasses are to be used for covering films 
spread upon slides (as is generally the.case if the 
method recommended in this book is adopted) it is 
quite sufficient to wipe them carefully with a clean 
handkerchief moistened with spirit and then to dry 
them. . 
After slides or cover-glasses have been cleaned the 
utmost care must be taken that they do not come in 
contact with the skin, or a thin film of grease will be 
deposited upon them. 
PIPETTES. 
Glass pipettes for the collection of pathological fluid 
for bacteriological examination are in daily use in the 
laboratory, and are very necessary for practitioners who 
wish to send fluids for examination. They are readily 
made from a piece of quill glass tubing, and a few 
should always be kept in stock against emergencies. 
