172 



The Philippine Journal of Science 



1916 



These results show that a considerable variation in concentra- 

 tion of sugars has no appreciable effect on the total acid produced 

 and that here, as elsewhere, the acid production by any one strain 

 with the same sugar is remarkably constant. There is again 

 demonstrated, however, a consistent although slight difference 

 among the strains. 



In order to obtain direct evidence as to whether the acidities 

 attained in the 0.5 series had in any degree been determined 

 by the low sugar concentration, a number of 1 per cent sugars 

 was similarly tested. To learn, further, whether a simpler 

 nutrient vehicle for the carbohydrates, would modify the amount 

 of acid produced, a small series was also tested in a solution 

 containting 2 per cent peptone and 0.5 per cent sodium chloride. 

 The results of these series are included in Table VI. 



Table VI. — Total acidities attained in 1 per cent carbohydrate fluid media, 

 in terms of cubic centimeters of normal sodium, hydroxide. 



Strain. 



A 

 B 

 C- 

 D . 

 E . 

 P 

 G . 

 H 

 I.. 

 J . 



Controls: 



1 



2 



Bouillon 1 per cent. > 



Levu- 

 loBe. 



2.16 



2.3 



2.2 



2.2 



2.1 



(0) 



1.8 



2.1 



2.1 



2.0 



1.00 



1.00 



Malt- 

 ose. 



1.7 



1.5 



1.7 



1.55 



1.6 



1.65 



1.45 



1.45 



1.65 



1.2 



1.00 

 1.00 



Salicin. 



1.7 



1.8 



2.0 



1.7 



1.25 



2.3 



1.2 



1.0 



(b) 



1.15 



0.55 

 0.46 



Arabin- 

 ose. 



2.0 



2.0 



2.2 



2.05 



2.1 



1.95 



1.7 



2.05 



2.1 



1.35 



1.25 

 1.15 



Galac- 

 tose. 



1.85 



1.9 



1.8 



1.85 



1.8 



1.65 



1.3 



1.7 



1.75 



1.85 



0.80 

 0.90 



Peptone waters, 1 per cent. • 



Malt- 

 ose. 



2.3 



2.5 



0.95 



1.5 



2.5 



1.9 



1.36 



2.35 



2.35 



1.3 



1.00 

 0.90 



Sali- 

 cin.": 



0.75 

 (0.05) 



1.15 

 (0. 45) 



0.75 

 (0. 05) 



0.75 

 (0. 05) 



0.95 

 (0.25) 



0.9 

 (0.20) 



0.85 

 (0. 15) 



0.7 

 (0.0) 



0.85 

 (0. 15) 



0.9 

 (0.20) 



0.65 

 0.70 



Arabin- 

 ose. 



2.6 



2.65 



2.75 



2.66 



2.45 



2.0 



1.95 



1.85 



2.2 



1.95 



1.30 



Galac- 

 tose. 



2.4 



2.4 



2.2 



2.3 



2.36 



2.3 



1.65 



1.46 



2.1 



2.5 



1.10 

 1.1B 



" Titrated with test N/50 sodium hydroxide. 



^ No growth. 



<^ Figures in parentheses represent apparent increase in acid. 



Comparison of these results with those given in Table III 

 shows that in no case was there a radical increase of acidity in 

 the 1 per cent series. Contrasting the bouillon and peptone 



