THE MICROSCOPE 23 
may be combined with alkalin pyrogallol and give an atmosphere which 
is entirely free from oxygen. 
Petri Dish 10 em diam. 
Fig. 23.—Jones Anaerobic Culture Apparatus. 
Annular Groove 
8mm. Deep x 
fmm Wide. 
Cross-section of the Stone Base with 
Petri Dish in Position. 
Bulloch’s Method. This is very similar to Novy’s and needs no 
special attention here. 
inert gas. 
Jones’ Method. This method 
allows the observation of growth 
and requires very little gas. It is 
described by the author as follows: 
“The apparatus consists of one-half 
of a Petri dish sealed with paraffin 
on a square stone or metal base 
provided for an inlet of the inert 
gas and outlet of air. The figure 
gives the general construction of the 
apparatus. 
Tar Microscope 
A compound microscope is 
necessary for a study of bacteria. 
The suecess which a student has 
in the pursuit of microbiology is 
often dependent upon thorough 
knowledge of the microscope. It is 
desirable to study the microscope 
with much care in order to under- 
stand its limitations and the sig- 
nificance of each part. It is much 
better to regard it as a delicate 
piece of mechanism through whose 
intelligent use an entire world of 
living organisms will be made visi- 
The air in the Jar should be replaced by an 
Byes Lens 
ed 
of the 
Ocular 
Diaphragm 
Field Lens 
Draw Tube 
# 
§ 
© 
ma 
3 
a Body Tube 
pa 
poh 
wad 
a 
1 |. Draw Tube Diaphgram 
with Society Screw 
Society Screw 
# 
ne Mont 
of the 
Objeetive 
<a Back Lens 
VDC Middle Lens 
Pio Front Lens 
Cover Glase RZ ve Working Distance 
Shde 
Object | 
Fig. 24.—Showing Cross-section of a 
Microscope. 
(Courtesy of the Spencer Lens Company ) 
