580 Bulletin 167 



Sixth day. — Immediate nitrite reaction occurred in the fol- 

 lowing: Ps. mcscnterica, XXXVI, LI and a trace in Ps. fluo- 

 resceins, while nitrates were found in all. No gas was observed. 

 A test for nitrites was also made by the naphthlamine-sulphanilic 

 acid reagent. A positive reaction was obtained with Ps. mesetv- 

 terica, XXXVI, LI, and Ps. fluorcsccns. In the latter the color 

 was not as deep as in the others. 



Eleventh day. — Only slight clouding in the open arm was 

 observed ; no gas was produced. A positive nitrite reaction was 

 obtained with Ps. fluorcsccns, Ps. mcscnterica, XXXVI, and LI. 

 Nitrates and ammonia were present in all by the diphenylamine 

 and Nessler's reagents respectively. A strong reaction with 

 Nessler's reagent was given by Ps. putrida, Ps. fluorcsccns, CXII, 

 and CXLVIII. 



4. Indol. — The tests for indol on nutrient broth and on 

 Dunham's peptone solution were made by adding 10 drops of 

 chemically pure sulphuric acid and 1 cc. of .02% sodium nitrite to 

 10 cc. of culture. The tubes were allowed to stand 10 minutes 

 and then heated. Strains Ps. alba and CXL gave a trace of a 

 reaction in 10 minutes without heating. The results on nutrient 

 broth are given in table 69 and those on Dunham's peptone 

 solution in table 70. A positive result is indicated by +, a 

 negative by — , and a trace by ± . 



TABLE G9. IXDOL PRODUCTION IX NUTRIENT BROTH. 



Strain 10 13 18 20 22 24 26 30 30 30 37 40 40 40 60 



(1. d. d. d. d. d. d. d. d. d. d. d. d. d. d. 



/'.v. alba, + + + + + — + ± + — ±± + + 



Ps. fluor.. — — — — — — — — — — — ± — — — 



Ps. longa, ■ — — ■ — ± — — ± ± ± ± — — — — + 



Ps. vies., — — — ■ — — — — — — — ■ — — ■ — ± 



Ps. tenuis. — — — — — — — — — ■ — — — ± 



Ps. putrida, — — — — — — — ■ — — ■ — — — — — — 



CXII, _______ — — _ — ± 



CXV, ____ — _______ — _ — 



CXL, + + + + + + + + + + ± + + + + 



CXLV, ___ — _ — — ± 



CXLVIII, — ± 



XXXVI, — ± — — ± — — 



LI, — — — — — ±±±±± — ± 



