1920] 
CHAMBERS—BACTERIAL INHIBITION BY METABOLIC PRODUCTS 281 
TABLE X 
GROWTH poss HYDROGEN ION CONCENTRATION OF TD COLI AT 
iL pe CENT DEXTROSE BOUILLON yy và AIN 
OUILLON 4-HCl AT INTERVAL 
1 2 
1% dextrose bouillon Plain bouillon + HCl 
Hours 
: : Cc. of 
Bacteria Bacteria 
Pu per cc. N/5 HCl Pu 
added 
0 55,000 1l 57,000 T 
12 268,000,000 5.3 179,000,000 6.7 
14 15 5.2 
20 281,000,000 5.1 
24 214,000,000 4.9 178,000,000 5.3 
26 4 5.0 
36 - 220,000,000 4.8 197,000,000 5.2 
38 5 4.9 
48 189,000,000 4.8 175,000,000 5.1 
50 5 4.7 
60 4.9 
72 119,000,000 4.8 116,000,000 5.0 
74 3 4.7 
96 14,500,000 4.9 71,000,000 4.9 
120 11,100 4.9 96,000,000 5.3 
122 3 4.9 
144 0 4.9 55,000,000 5.1 
146 2 4.9 
168 26,000,000 4.9 
192 60,000,000 5.1 
194 : 2 4.9 
234 74,000,000 4.9 
276 144,000,000 5.3 
278 4 4.9 
348 148,000,000 5.1 
350 3 4.8 
492 95,000,000 4.9 
612 73,000,000 5.1 
DISCUSSION 
For a discussion of the combined results embodied in the 
experimental data presented, the inhibitory products of meta- 
bolism of Bacillus coli are divided under four topics: “auto- 
toxins"; H ions; OH ions; and products of dextrose fermenta- 
tion other than those directly related to changes in H ion con- 
centration. 
