216 IVAN E. WALLIN 
C. Action of acetic acid on bacteria 
Acetic acid of various strengths was permitted to act on bacteria 
for a period of six hours. Glacial acetic acid was diluted with 
distilled water for the various dilutions. 
a. After 0.5 per cent acetic acid. 1. Human tubercle bacilli. 
Bacilli disintegrated. Granular remains intensely stained 
(black). 
2. Bovine tubercle bacilli. Many bacilli retain their form, 
others disintegrated. Intensely stained. 
3. Unknown bacilli, culture from intestinal contents of kitten. 
Bacilli unstained, swollen, and coalesced. 
4. Bacillus megatherium. Bacilli could not be demonstrated 
by staining. Spores swollen. 
5. Staphylococcus albus. Swollen, unstained, and partially 
coalesced. 
b. After 1 per cent acetic acid. 1. Human tubercle bacilli. 
Bacilli could not be demonstrated by staining. Remains granu- 
lar, intensely stained. 
2. Bovine tubercle bacilli. Bacilli could not be demonstrated 
by staining. Remains granular, faintly stained. ro 
3. Unknown bacilli, culture from intestinal contents of kitten. 
Bacilli unstained, swollen, and distorted. 
4, Bacillus megatherium. Bacilli unstained and distorted. 
Many forms contain ‘bleb’-like swellings at end or center of 
bacillus, some contain two or three outpushings. Figure 7 is 
a free-hand drawing of a few of these bacilli. 
5. Staphylococcus albus. Appear partially dissolved and coa- 
lesced. Unstained. 
c. After 3 per cent acetic acid. 1. Human tubercle bacilli. 
Form of bacilli partially preserved. Faintly stained. 
2. Bovine tubercle bacilli. Bacilli appear quite normal and 
well stained. Some appear to have vacuoles. 
3. Unknown bacilli, culture from intestinal contents of kitten. 
Bacilli could not be demonstrated by staining. Remains, amor- 
phous and faintly stained. 
4. Bacillus megatherium. Few unstained bacilli that appeared 
partially dissolved. Spores coalesced. 
Mate 
