53 



Result. — This fluid exertod a profound rostrainino^ influence. In 

 two of the tubes the first bacterial cloudinii' ai)peaied on the seven- 

 teenth (lay. at whicli tiin(^ there was no rim of o-ernis, pellicle, or pre- 

 cipitate. The other -1 tu])es v/erc 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 (MO'hth day and put into tubes of alkaline beef ])roth did not 

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

 nuiltiplication 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 magniflcent 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 litnms; there 

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

 low precipitate 5 to 6 mm. deep. The rim was homogeneous, i. e., not 

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

 the rim in tubes of alkaline beef broth inoculated directlv 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 RidgwaN^'s tables it exactly matched 

 his chrome yellow (VI-8). On the flfty-second day all the tubes were 

 alike. Each had a thick dark 3^ellow 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 Avas 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, flshy odor suggestive of amin compounds. On 

 boiling, gases were given ofl" which immediateh^ and strongl}^ blued 

 innitral litmus papei'. Conducted into a tube of Xessler's solution, the 

 vaj)or fi-om the i)oiling fluid caused an immediate copious rust}^ pre- 

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

 the fllt(U"(Hl fluid into Nessler's solution, but no such reaction could be 

 ol)tained 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 confldent that either one is of any value. The fluid did not 

 redden with a small quantity of phenolphthalein, ))ut reacted with a 

 larger (juantity. Titrated in ice water with G c. c. of the standard solu- 

 tion of phenolphthalein, ?> c. c. of the fluid re<iuiied(>.2()c. c. of — HCl; 



titrated with neutral litmus, 3 c. c. recpiired (). 30 c. c. of ^ HCl. It 



was dithcult to drive ofl all the volatile alkalies by boiling, the blue 

 reaction on wet litnms pai)er showing plainly in the steam when the 

 fluid was half lioiledaway. 



