53 



Bemdt. — This fluid exerted a profound restraining influence. In 

 two of the tubes the first bacterial clouding appeared on the seven- 

 teenth day, at which time there was no rim of germs, pellicle, or pre- 

 cipitate. The other 2 tubes were not clouded on the seventeenth 

 day, but on the thirty-seventh day, when next examined, there was a 

 copious growth in each. A large loop taken from each of these 2 tubes 

 on the eighth day and put into tubes of alkaline beef broth did not 

 cloud the latter until the fifth day, from which we may infer that 

 multiplication had gone on in the acid broth very slowly. When once 

 the restraining influence was overcome, the organism ran riot in the 

 fluid making a magnificent and long continued growth, more growth in 

 fact than I had been able to obtain with any other fluid. On the thirty- 

 seventh day the fluid in each tube was plainly alkaline to litmus; there 

 was no pellicle but a dense bright yellow rim i mm. wide, and a yel- 

 low precipitate 5 to mm. deep. The rim was homogeneous, i. e., not 

 composed of scattered yellow zoogloea^on a paler film, as was, however, 

 the rim in tubes of alkaline beef broth inoculated directly from these 

 cultures. This rim was wrinkled, or traversed crosswise, by many 

 denser bands. The color of the bacteria was as bright as in the vessels 

 of the host plant; compared with Ridgway's tables it exactly matched 

 his chrome yellow (VI-S). On the fifty-second day all the tubes were 

 alike. Each had a thick dark yellow ring above the fluid, and a copi 

 ous, distinctly yellow pellicle. The fluid was nearly clear and dis- 

 tinctly pale brown, which was not the case with the broth in theunin- 

 oculated tubes. The yellow precipitate was three times as abundant as 

 that obtained in alkaline beef broth, i. e., 6 to 7 mm. deep. The fluid 

 was now strongly alkaline, and the germs were somewhat ropy. The 

 cultures had a feeble, fishy odor suggestive of amin compounds. On 

 boiling, gases were given off which immediately and strongly blued 

 neutral litmus paper. Conducted into a tube of Nessler's solution, the 

 vapor from the boiling fluid caused an immediate copious rusty pre- 

 cipitate. The same result was obtained by putting one-fourth c.c. of 

 the filtered fluid into Nessler's solution, but no such reaction could be 

 obtained from the uninoculated fluid. An attempt was made to deter- 

 mine the amount of alkalies present and the results are given, but I 

 am not confident that either one is of any value. . The fluid did not 

 redden with a small quantity of phenolphthalein, hut reacted with a 

 larger quantity. Titrated in ice water with 6 c. c. of the standard solu- 



N 

 tion of phenolphthalein, H c c. of the fluid required 0.20 c. c. of — HCl; 



N 

 titrated with neutral litmus, 3 c. c. required 0. 30 c. c. of — HCl. It 



was difficult to drive off all the volatile alkalies by boiling, the blue 

 reaction on wet litmus paper showing plainly in the steam when the 

 fluid was half boiled away. 



